Methods and compositions for stabilizing trans-splicing intein modified proteases

ABSTRACT

Methods for producing a trans-splicing intein-modified protease with enhanced solubility and regulating its activity are described. Intein-modified proteases having enhanced solubility and polynucleotides encoding the same are provided. Methods of storing trans-splicing proteases are also described.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 62/069,653, which was filed Oct. 28, 2014 and is incorporated herein by reference as if fully set forth.

The sequence listing electronically filed with this application titled “Sequence Listing,” which was created on Oct. 28, 2015 and had a size of 59,091 bytes is incorporated by reference herein as if fully set forth.

FIELD

The disclosure relates to methods and compositions enabling tight regulation of trans-splicing intein modified protease activity in liquid detergents and home care products, for stable storage in the formulations and efficient recovery of protease activity quickly, with reduced loss of cleaning efficiency.

BACKGROUND

Proteases are common ingredients in a variety of liquid detergents, laundry detergents, dish-washing liquids, paints, coatings and industrial cleaners. Proteases are notoriously difficult to handle in formulations because they not only degrade other proteins but can self digest. Therefore protease stabilization remains one of the biggest challenges facing the liquid detergent industry. Current stabilization technologies are often based on the use of high concentrations of chemical protease inhibitors, increasing the chemical load and cost. It would be desirable to have a more environmentally friendly, bio-based and low cost solution to stabilize protease enzymes but without compromising product performance. Previously it was demonstrated that the trans-splicing intein technology could be used to control protease activity.

SUMMARY

An aspect of the invention relates to an intein-modified protease. The intein-modified protease comprises a first precursor and a second precursor. The first precursor comprises an N-extein of a target protease and a solubility enhanced N-intein of a trans-splicing intein. The carboxy terminus of the N-extein is fused to the amino terminus of the solubility enhanced N-intein. The second precursor comprises a solubility enhanced C-intein of the trans-splicing intein and a C-extein of the target protease. The carboxy terminus of the solubility enhanced C-intein is fused to the amino terminus of the C-extein. The first precursor is separated from the second precursor prior to splicing. The intein-modified protease has enhanced solubility and reduced activity compared to the target protease. The activity of the target protease is obtained upon trans-splicing of the intein-modified protease and fusion of the N-extein and the C-extein.

An aspect of the invention relates to an expression cassette. The expression cassette comprises one or more polynucleotides encoding a first precursor or a second precursor of an intein-modified protease. The first precursor comprises an N-extein of a target protease and a solubility enhanced N-intein of a trans-splicing intein. The carboxy terminus of the N-extein is fused to the amino terminus of the solubility enhanced N-intein. The second precursor comprises a solubility enhanced C-intein of the trans-splicing intein and a C-extein of the target protease. The carboxy terminus of the solubility enhanced C-intein is fused to the amino terminus of the C-extein. Upon expression from the expression cassette the first precursor would be separated from the second precursor prior to splicing. The intein-modified protease would have enhanced solubility and reduced or inhibited activity compared to the target protease. The activity of the target protease would be restored upon trans-splicing of the intein-modified protease and fusion of the N-extein and the C-extein.

An aspect of the invention relates to a composition comprising: a first precursor of an intein-modified protease and a second precursor of an intein-modified protease. The first precursor comprises an N-extein of a target protease fused to a solubility enhanced N-intein of a trans-splicing intein. The carboxy terminus of the N-extein is fused to the amino terminus of the solubility enhanced N-intein. The second precursor comprises a solubility enhanced C-intein of the trans-splicing intein fused to a C-extein of the target protease. The carboxy terminus of the solubility enhanced C-intein is fused to the amino terminus of the C-extein. The first precursor is separated from the second precursor prior to trans-splicing. The intein-modified protease has enhanced solubility and reduced activity compared to the target protease and the activity of the target protease is obtained upon trans-splicing of the intein-modified protease and fusion of the N-extein and the C-extein.

An aspect of the invention relates to a home care product that includes any one of the intein-modified proteases or the compositions disclosed herein, and one or more effectors.

An aspect of the invention relates to a method of regulating protease activity. The method comprises forming any one of the home care products disclosed herein.

An aspect of the invention relates to a method of storing a protease in a mixture. The method includes making any one of intein-modified proteases or the compositions disclosed herein. The method also includes combining the intein-modified protease or the composition with at least one agent selected from the group consisting of: a detergent, a soap, an industrial cleaner, and a dishwashing liquid with one or more effectors to form a mixture.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of the embodiments of the present invention will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It is understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:

FIG. 1 illustrates schematic drawings of solubility optimized trans-splicing NI and IC.

FIGS. 2A-2B illustrate expression of solubility optimized NI and IC in E. coli. FIG. 2A illustrates total protein profiles. FIG. 2B illustrates soluble protein profiles.

FIGS. 3A-3E illustrate results of detergent supplement screenings for dilution inducible iProtease activity determined for sodium salt supplements (FIG. 3A), for potassium salt supplements (FIG. 3B), for ammonium and lithium salt supplements, (FIG. 3C), for charged polymeric salt supplements (FIG. 3D), and for polyol supplements (FIG. 3E).

FIGS. 4A-4B illustrate that salt supplements perform similarly in different detergent contexts: the Detergent-2 (FIG. 4A) and the Detergent-1 (FIG. 4B).

FIGS. 5A-5B illustrate that KCl reversibly inhibits iProtease activity in aqueous buffer. FIG. 5A illustrates dilution induction. FIG. 5B illustrates salt suppression.

FIGS. 6A-6B illustrate that KCl promotes association of the splicing precursors. FIG. 6A illustrates iProtease activity in serial dilutions of the high salt associated (NI+IC) premix in the BR buffer. FIG. 6B illustrates iProtease activity in mixes of separate serial dilutions of NI and IC (NI−IC) in the BR buffer.

FIGS. 7A-7B illustrate Coomassie gels that show splicing after mixing of the splicing precursors. FIG. 7A illustrates protein profiles after dilution of the unsalted premix in the aqueous buffer. FIG. 7B illustrates protein profiles after dilution of the salted premix in the aqueous buffer.

FIGS. 8A-8B illustrate benchmarks dilution inducible iProtease activity to 1% Savinase. FIG. 8A illustrates the dilution activity profile of iProtease. FIG. 8B illustrates the dilution activity profile of Savinase.

FIGS. 9A-9B illustrate that the KCl stabilized (NI+IC) premix has no enzyme activity for iProtease (FIG. 9A) and Savinase (FIG. 9B).

FIGS. 10A-10B illustrate storage stability of the KCl stabilized (NI+IC) premix in the aqueous buffer. FIG. 10A illustrates iProtease activity for the premix not stored. FIG. 10B illustrates iProtease activity for the premix stored for 8 weeks.

FIGS. 11A-11B illustrate that the KCl stabilized (NI+IC) premix can be formulated to the Detergent-1 without loss of the dilution inducible activity. FIG. 11A illustrates the dilution activities from 1M KCl.

FIG. 11B illustrates the dilution activities from 50% Detergent-1 lacking 1M KCl.

FIG. 12 illustrates that KCl has dual roles in detergent formulation: stabilize (NI+IC) premix for formulation and maintain stability in detergent.

FIG. 13 illustrates that iProtease storage stability in Detergent-1 is comparable with Savinase under accelerated ageing conditions.

FIG. 14 illustrates in detergent dilution assays that KCl stabilized (NI+IC) premix is compatible with four liquid laundry detergents.

FIG. 15 illustrates that stain removal efficacy of detergent formulated iProtease is comparable with Savinase in four liquid laundry detergents.

FIG. 16 illustrates stability of dilution inducible iProtease activity in three liquid laundry detergents under accelerated ageing conditions.

FIG. 17 illustrates stain removal stability under accelerated aging conditions in three liquid laundry detergents.

FIG. 18 illustrates a bi-cistronic expression cassette for expressing NI and IC and includes a nucleic acid sequence of the frameshifted RBS of SEQ ID NO: 48.

FIGS. 19A and 19B illustrate protease activity from in vitro trans-splicing three hours after IPTG induction. FIG. 19 A illustrates protease activity following splicing of inteins 12, 12, 44, 46, 47, 50, 79, 81 and 103. FIG. 19B illustrates protease activity following splicing of inteins 110, 116, 123, 128, 135, 143, and 150.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Certain terminology is used in the following description for convenience only and is not limiting. The words “a” and “one,” as used in the claims and in the corresponding portions of the specification, are defined as including one or more of the referenced item unless specifically stated otherwise. This terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import. The phrase “at least one” followed by a list of two or more items, such as “A, B, or C,” means any individual one of A, B or C as well as any combination thereof.

An embodiment comprises an intein-modified protease having enhanced solubility. The intein-modified protease may comprise components that together comprise a target protease and an intein fused to the target protease in such a position as to control the activity of the target protease. Both the target protease and the intein are split into two parts, and one part of the target protein is fused with one part of the intein, while the other part of the target protein is fused to the other part of the intein. Although the two fused sequences are separate entities, they are collectively referred to herein as an “intein-modified protease.” The separate fusions may be referred to as a “first precursor” and “second precursor.” Collectively, the first precursor and the second precursor may be referred to as components of the intein-modified protease. As used herein, N-extein and N-intein refer to the amino terminal parts of the target protease and intein, respectively. Likewise, C-extein and C-intein refer to the carboxy terminal parts of the target protease and intein, respectively.

The intein in an intein-modified protease is a trans-splicing intein capable of effecting trans-splicing of the intein-modified protease. The first precursor comprises an N-extein of the target protease and a solubility enhanced N-intein of the trans-splicing intein. The carboxy terminus of the N-extein may be fused to the amino terminus of the solubility enhanced N-intein. The solubility enhanced N-intein may comprise a first solubility enhancer. The carboxy terminus of the N-intein may be fused to the first solubility enhancer by a first linker. The second precursor comprises a solubility enhanced C-intein of the trans-splicing intein and a C-extein of the target protease. The carboxy terminus of the solubility enhanced C-intein may be fused to the amino terminus of the C-extein. The solubility enhanced C-intein may comprise a second solubility enhancer. The second solubility enhancer may be fused to the amino terminus of the C-intein by a second linker. The first precursor is separated from the second precursor prior to splicing of the intein-modified protease.

In an embodiment, at least one of the first solubility enhancer or the second solubility enhancer may comprise, consist essentially of, or consist of a thioredoxin domain (Trx), small ubiquitin-related protein (SUMO), glutathione-S transferase (GST), maltose-binding protein (MBP), N utilization substance (A NusA), or seventeen kilo Dalton protein (Skp). The first solubility enhancer may be the same or different solubility enhancer than the second solubility enhancer. At least one of the first solubility enhancer or the second solubility enhancer may be Trx. The first solubility enhancer may comprise, consist essentially of, or consist of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100% identity to SEQ ID NO: 51. The second solubility enhancer may comprise, consist essentially of, or consist of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100% identity to SEQ ID NO: 53. A solubility enhancer may any other molecule capable of enhancing solubility of the first precursor or the second precursor. A solubility enhancer may be covalently linked or fused to an intein.

In an embodiment, the first linker or the second linker may be any linker suitable for linking a solubility enhancer to the N-intein or the C-intein. The linker may be of variable length, composition and flexibility. The linker may be short and flexible. The linker may comprise a stretch of glycine (G) and serine (S) residue. The linker may include an amino acid sequence of GGGGS (SEQ ID NO: 55), GGGGGS (SEQ ID NO: 56) or GGGGG (SEQ ID NO: 57). The linker may be configured to define a small structural turn to keep the solubility enhancer domains of the first precursor or the second precursor away from the interface of the split intein pair. Structural modeling can be used to predict the best fit length and composition of the linker.

In an embodiment, at least one of the first linker or the second linker may be a DPNG linker. The DPNG linker may comprise an amino acid sequence of SEQ ID NO: 5. The first linker or the second linker may be any other suitable linker.

The target protease may be any protease. As described, the target protease is split into two parts when intein modified, and the intein modified parts will comprise the first precursor and the second precursor. As used herein, “protease” refers to an enzyme or portion thereof that catalyzes hydrolysis of peptide bonds. The enzyme may be but is not limited to an amino acid sequence or protein herein having the activity of catalyzing hydrolysis of peptide bonds. The enzyme may be a variant of an amino acid sequence or protein herein and have the activity of catalyzing hydrolysis of peptide bonds, where the variant is a mutant and/or part of the amino acid sequence or protein. The variant may have at least 40% of the activity of the amino acid sequence or protein having the activity of catalyzing hydrolysis of peptide bonds. Activity may be analyzed by the enzyme assay outlined in Example 2 with respect to Savinase activity.

The target protease may be an enzyme classified under EC 3.4 as peptide hydrolases. The target protease be one classified under EC 3.4.99, EC 3.4.21.62, serine proteases, alkaline proteases, keratinases, and others. The target protease may be but is not limited to: a metallo protease, a cysteine protease, an aspartate protease, or an ATP-dependent protease.

In an embodiment, the target protease may be an alkaline protease. The alkaline protease may be a protease from Subtilisin family. The target protease may be a Subtilisin from B. lentus (BL, P29599); Subtilisin from B. pumilus (P07518); Subtilisin from B. subtilis (E, P04189); Subtilisin from B. licheniformis (DY, P00781); Subtilisin from B. amyloliquefaciens (BPN, P00782); Subtilisin from Bacillus sp. strain TA39 (P28842); Subtilisin from Geobacillus stearothermophilus (J, P29142); Subtilisin from B. subtilis subsp. Natto (NAT, P35835); Subtilisin from B. licheniformis (Carlsberg, P00780); Subtilisin from B. subtilis subsp. Amylosacchariticus, (amylosacchariticus, P00780); Subtilisin Carlsberg; Subtilisin BPN; or Subtilisin SAPB from Bacillus pumilus (CBS).

The protease from the Subtilisin family may be Savinase. Savinase is an extracellular alkaline protease from Bacillus lentus (Uniprot accession number is: P29600 (http://www.uniprot.org/uniprot/P29600) and a common protease in liquid laundry detergents. The target protease may comprise, consist essentially of, or consist of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100% identity to a sequence of SEQ ID NO: 6, which is a sequence of Savinase, P29600.

The target protease may be a protease from Bacillus licheniformis (UniProt accession number is: Q6PNN5. The target protease may comprise, consist essentially of, or consist of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100% identity to a sequence of SEQ ID NO: 8, which is a sequence B. licheniformis protease, Q6PNN5.

The target protease may be an acid protease. Acid proteases are widely used in cheese making, food. and feed. preparation and in the leather industry. The acid protease may be a bacterial protease, a fungal protease or a mammalian protease. The acid. protease may be an aspartic proteinase aspergillopepsin A (pepA) from Aspergillus flavus (UniProt accession number is: B8NLY9 (PEPA_ASPFN)). The target protease may comprise, consist essentially of, or consist of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100% identity to a sequence of SEQ ID NO: 9, which is a sequence of an aspartic proteinase aspergillopepsin A (pepA) from Aspergillus flavus, B8NLY9 (PEPAASPFN).

The intein may be any intein. The intein may be an intein naturally capable of trans-splicing. The intein may be a cis-splicing intein engineered for trans-splicing. Methods of engineering cis-splicing inteins into artificial trans-splicing inteins and testing artificially split inteins for restoration of protease activity are described in Examples 17 and 18 herein. Inteins are polypeptides that have the ability to cleave themselves from proteins post-translationally and may mediate ligation of the remaining protein fragments (the exteins), and may have the ability to cleave DNA at specific sites for their propagations. The intein may be modified. Modified inteins may have the ability to cleave themselves but may lose their ability to cleave the DNA. The intein may be but is not limited to mTth, Pho_RadA, Tko_RadA, Sce_VMA, mVMA, and Pab_Lon. The intein may be one found in InBase, the intein database (http://www.neb.com/neb/inteins.html; Perler et al. 1992 Proc Natl Acad Sci USA 89: 5577), which is incorporated by reference herein as if fully set forth.

The intein may be one of APMVPol (Acanthomoeba polyphaga Mimivirus), AbrPRP8 (Aspergillus brevipes FRR2439), Aca-JER2004PRP8 (Ajellomyces capsulatus), Aca-H143PRP8 (Ajellomyces capsulatus 11143), Ade-ER3PRP8 (Ajellomyces dermatitidis ER-3), Aca-NAm1PRP8 (Ajellomyces capsulatus NAm1), Afu-Af293PRP8 (Aspergillus fumigatus var. ellipticus strain Af293), Ade-SLH14081PRP8 (Ajellomyces dermatitidis SLH14081), Afu-FRR0163PRP8 (Aspergillus fumigatus strain FRR0163), Afu-NRRL5109PRP8 (Aspergillus fumigatus var. ellipticus strain NRRL 5109), Ani-FGSCA4PRP8 (Aspergillus nidulans FGSC A), Agi-NRRL6136PRP8 (Aspergillus giganteus Strain NRRL 6136), AviPRP8 (Aspergillus viridinutans strain FRR0577), BciPRP8 (Botrytis cinerea), Bde-JEL423PRP8-1 (Batrachochytrium dendrobatidis JEL423), Bde-JEL197RPB2 (Batrachochytrium dendrobatidis JEL197), Bde-JEL423e1F-5B (Batrachochytrium dendrobatidis JEL423), Bde-JEL423PRP8-2 (Batrachochytrium dendrobatidis JEL423), Bfu-B05PRP8 (Botryotinia fuckeliana B05.10), Bde-JEL423RPC2 (Batrachochytrium dendrobatidis JEL423), CIVRIR1 (Chilo iridescent virus), CV-NY2AORF212392 (Chlorella virus NY2A), CV-NY2ARIR1 (Chlorella virus NY2A), CZIVRIR1 (Costelytra zealandica iridescent virus), Cba-WM02.98PRP8 (Cryptococcus bacillisporus strain WM02.98), Cba-WM728PRP8 (Cryptococcus bacillisporus strain WM728), CeuClpP (Chlamydomonas eugametos), CgaPRP8 (Cryptococcus gattii), ClaPRP8 (Cryptococcus laurentii strain CBS139), CmoClpP (Chlamydomonas moewusii strain UTEX 97), CmoRPB2 (Chlamydomonas moewusii strain UTEX 97), Cg1VMA (Candida glabrata), CpaThrRS (Candida parapsilosis strain CLIB214), Fne-APRP8 (Filobasidiella neoformans Serotype A), Cne-JEC21PRP8 (Cryptococcus neoformans JEC21), Fne-ADPRP8 (Cryptococcus neoformans Serotype AD), CreRPB2 (Chlamydomonas reinhardtii), CroVRPB2 (Cafeteria roenbergensis virus BV-PW1), CroVRIR1 (Cafeteria roenbergensis virus BV-PW1), CroVPol (Cafeteria roenbergensis virus BV-PW1), CroVTop2 (Cafeteria roenbergensis virus BV-PW1), CtrThrRS (Candida tropicalis ATCC750), CstRPB2 (Coelomomyces stegomyiae), CtrVMA (Candida tropicalis), DdiRPC2 (Dictyostelium discoideum strain AX4), DhanVMA (Debaryomyces hansenii CBS767), Ctr-MYA3404VMA (Candida tropicalis MYA-3404), DhanGLT1 (Debaryomyces hansenii CBS767), FteRPB2 (Floydiella terrestris strain UTEX 1709), GthDnaB (Guillardia theta), EniPRP8 (Emericella nidulans R20), Eni-FCSGA4PRP8 (Emericella nidulans FGSC A4), HaV01Pol (Heterosigma akashiwo virus 01), HcaPRP8 (Histoplasma capsulatum), IIV6RIR1 (Invertebrate iridescent virus 6), Kex-CBS379VMA (Kazachstania exigua strain CBS379), Kla-CBS683VMA (Kluyveromyces lactis strain CBS683), Kla-IFO1267VMA (Kluyveromyces lactis IFO1267), Kla-NRRLY1140VMA (Kluyveromyces lactis NRRL Y-1140), Le1VMA (Lodderomyces elongisporus), NauPRP8 (Neosartorya aurata NRRL 4378), Mca-CBS113480PRP8 (Microsporum canis CBS 113480), NfiPRP8 (Neosartorya fischeri), Nfe-NRRL5534PRP8 (Neosartorya fennelliae NRRL 5534), Ngl-FRR1833PRP8 (Neosartorya glabra FRR1833), Ngl-FR2163PRP8 (Neosartorya glabra FRR2163), NquPRP8 (Neosartorya quadricincta strain NRRL 4175), NspiPRP8 (Neosartorya spinosa FRR4595), Pabr-Pb01PRP8 (Paracoccidioides brasiliensis Pb01), Pabr-Pb03PRP8 (Paracoccidioides brasiliensis Pb03), PanGLT1 (Podospora anserina), PanCHS2 (Podospora anserina), PchPRP8 (Penicillium chrysogenum), Pb1PRP8-a (Phycomyces blakesleeanus), Pbr-Pb18PRP8 (Paracoccidioides brasiliensis Pb18), Pb1PRP8-b (Phycomyces blakesleeanus), PexPRP8 (Penicillium expansum), PguGLT1 (Pichia guilliermondii), PnoGLT1 (Phaeosphaeria nodorum SN15), Pgu-altGLT1 (Pichia guilliermondii), PstVMA (Pichia stipitis CBS 6054), PnoRPA2 (Phaeosphaeria nodorum SN15), PpuDnaB (Porphyra purpurea), PtrPRP8 (Pyrenophora tritici-repentis Pt-1C-BF), PvuPRP8 (Penicillium vulpinum), PyeDnaB (Porphyra yezoensis), Sca-CBS4309VMA (Saccharomyces castellii strain CBS4309), SasRPB2 (Spiromyces aspiralis NRRL 22631), SceVMA, VMA (Saccharomyces cerevisiae), Sca-IFO1992VMA (Saccharomyces castellii strain IFO1992), Sce-DH1-1AVMA (Saccharomyces cerevisiae strain DH1-1A), ScarVMA (Saccharomyces cariocanus strain UFRJ 50791), Sce-Jay291VMA (Saccharomyces cerevisiae JAY291), Sce-YJM789VMA (Saccharomyces cerevisiae strain YJM789), Sce-OUT7091VMA (Saccharomyces cerevisiae OUT7091), Sce-OUT7112VMA (Saccharomyces cerevisiae OUT7112), SjaVMA (Schizosaccharomyces japonicus yFS275), Sex-IFO1128VMA (Saccharomyces exiguus strain IFO1128), SheRPB2 (Stigeoclonium helveticum strain UTEX 441), SdaVMA (Saccharomyces dairenensis strain CBS 421), SpaVMA (Saccharomyces pastorianus IFO11023), SpuPRP8 (Spizellomyces punctatus), SunVMA (Saccharomyces unisporus strain CBS 398), Tg1VMA (Torulaspora globosa strain CBS 764), TprVMA (Torulaspora pretoriensis strain CBS 5080), Ure-1704PRP8 (Uncinocarpus reesii), VpoVMA (Vanderwaltozyma polyspora strain CBS 2163), WIVRIR1 (Wiseana iridescent virus), ZroVMA (Zygosaccharomyces rouxii strain CBS 688), ZbiVMA (Zygosaccharomyces bisporus strain CBS 702), ZbaVMA (Zygosaccharomyces bailii strain CBS 685), AP-APSE ldpol (Acyrthosiphon pisum secondary endosymbiot phage 1), AP-APSE2dpol (Bacteriophage APSE-2), AP-APSE4dpol (Candidatus Hamiltonella defensa strain 5ATac bacteriophage), AP-APSE5dpol (Bacteriophage APSE-5), AP-Aaphi23MupF (Bacteriophage Aaphi23), AaeRIR2 (Aquifex aeolicus strain VF5), Aave-AAC001RIR1 (Acidovorax avenae subsp. citrulli AAC00-1), Aave-AAC001Aave1721 (Acidovorax avenae subsp. citrulli AAC00-1), Aave-ATCC19860RIR1 (Acidovorax avenae subsp. avenae ATCC 19860), AbaHyp-02185 (Acinetobacter baumannii ACICU), AceRIR1 (Acidothermus Cellulolyticus 11B), AehDnaB-1 (Alkalilimnicola ehrlichei MLHE-1), AehDnaB-2 (Alkalilimnicola ehrlichei MLHE-1), AehRir1 (Alkalilimnicola ehrlichei MLHE-1), MupFMupF (Aggregatibacter phage S1249), AhaDnaE-c (Aphanothece halophytica), AhaDnaE-n (Aphanothece halophytica), Alvi-DSM180GyrA (Allochromatium vinosum DSM 180), AmaMADE823 (Alteromonas macleodii), Amax-CS328DnaX (Arthrospira maxima CS-328), AovDnaE-c (Aphanizomenon ovalisporum), AovDnaE-n (Aphanizomenon ovalisporum), Apl-C1DnaX (Arthrospira platensis), AspDnaE-c (Anabaena species PCC7120), Arsp-FB24DnaB (Arthrobacter species FB24), AspDnaE-n (Anabaena species PCC7120), AvaDnaE-c (Anabaena variabilis ATCC29413), AvinRIR1BIL (Azotobacter vinelandii), AvaDnaE-n (Anabaena variabilis ATCC29413), Bce-MCO3DnaB (Burkholderia cenocepacia MCO-3), Bce-PC184DnaB (Burkholderia cenocepacia PC184), Bse-MLS10TerA (Bacillus selenitireducens MLS10), BsuP-M1918RIR1 (B. subtilis M1918 prophage), BsuP-SPBc2RIR1 (B. subtilis strain 168 Sp beta c2 prophage), Bcep1808_7358 (Burkholderia vietnamiensis G4), CP-P1201Thy1 (Corynebacterium phage P1201), CagRIR1 (Chlorochromatium aggregatum), CauSpoVR (Chloroflexus aurantiacus J-10-f1), CbP—C-StRNR (Clostridium botulinum phage C-St), CbP-D1873RNR (Clostridium botulinum phage D), Cbu-DugwayDnaB (Coxiella burnetii Dugway 5J108-111), Cbu—GoatDnaB (Coxiella burnetii MSU Goat Q177), Cbu-RSA334DnaB (Coxiella burnetii RSA 334), Cbu-RSA493DnaB (Coxiella burnetii RSA 493), CceHypl-Csp-2 (Cyanothece sp. ATCC 51142), CchRIR1 (Chlorobium chlorochromatii CaD3), CcyHyp1-Csp-1 (Cyanothece sp. CCY0110), CcyHyp1-Csp-2 (Cyanothece sp. CCY0110), Cfl-DSM20109DnaB (Cellulomonas flavigena DSM 20109), ChyRIR1 (Carboxydothermus hydrogenoformans Z-2901), CklPTerm (Clostridium kluyveri DSM 555), Cra-CS505DnaE-c (Cylindrospermopsis raciborskii CS-505), Cra-CS505DnaE-n (Cylindrospermopsis raciborskii CS-505), Cra-CS505GyrB (Cylindrospermopsis raciborskii CS-505), Csp-CCY0110DnaE-c (Cyanothece sp. CCY0110), Csp-CCY0110DnaE-n (Cyanothece sp. CCY0110), Csp-PCC7424DnaE-c (Cyanothece sp. PCC7424), Csp-PCC7424DnaE-n (Cyanothece sp. PCC7424), Csp-PCC7425DnaB (Cyanothece sp. PCC7425), Csp-PCC7822DnaE-n (Cyanothece sp. PCC 7822), Csp-PCC8801DnaE-c (Cyanothece sp. PCC 8801), Csp-PCC8801DnaE-n (Cyanothece sp. PCC 8801), CthATPaseBIL (Clostridium thermocellum), Cth-ATCC27405TerA (Clostridium thermocellum ATCC27405), Cth-DSM2360TerA (Clostridium thermocellum DSM 2360), CwaDnaB (Crocosphaera watsonii WH 8501), CwaDnaE-c (Crocosphaera watsonii WH 8501), CwaDnaE-n (Crocosphaera watsonii WH 8501), CwaPEP (Crocosphaera watsonii WH 8501), CwaRIR1 (Crocosphaera watsonii WH 8501), DaudRIR1 (Candidatus Desulforuclis audaxviator MP104C), DgeDnaB (Deinococcus geothermalis DSM11300), Dha-DCB2RIR1 (Desulfitobacterium hafniense DCB-2), Dha-Y51RIR1 (Desulfitobacterium hafniense Y51), Dpr-MLMS1RIR1 (delta proteobacterium MLMS-1), DraRIRl (Deinococcus radiodurans R1 TIGR strain), DraSnf2-c (Deinococcus radiodurans R1 TIGR strain), Snf2-nN-TERM (Deinococcus radiodurans R1 TIGR strain), Dra-ATCC13939Snf2 (Deinococcus radiodurans R1 ATCC13939 Brooks & Murray strain), UDPGD (Dictyoglomus thermophilum H-6-12), DvulParB (Desulfovibrio vulgaris subsp. vulgaris DP4), EP-Min27Primase (Enterobacteria phage Min27), FalDnaB (Frankia alni ACN14a), Fsp-CcI3RIR1 (Frankia species CcI3), GobDnaE (Gemmata obscuriglobus UQM2246), GobHyp (Gemmata obscuriglobus UQM2246), GviDnaB (Gloeobacter violaceus PCC 7421), GviRIR1-2 (Gloeobacter violaceus PCC 7421), GviRIR1-1 (Gloeobacter violaceus PCC 7421), HhalDnaB (Halorhodospira halophila SL1), Kfl-DSM17836DnaB (Kribbella flavida DSM 17836), KraDnaB (Kineococcus radiotolerans SRS30216), LLP-KSY1PolA (Lactococcus phage KSY1), LP-phiHSlChelicase (Listonella pelagia phage phiHSIC), Lsp-PCC8106GyrB (Lyngbya sp. PCC 8106), MP-BeDnaB (Mycobacteriophage Bethlehem), MP-Begp51 (Mycobacteriophage Bethlehem), MP-Cateragp206 (Mycobacteriophage Catera), MP-KBGgp53 (Mycobacterium phage KBG), MP-OmegaDnaB (Mycobacteriophage Omega), MP-Mcjw1DnaB (Mycobacteriophage CJW1), gp50 (Mycobacteriophage U2), Maer-NIES843DnaB (Microcystis aeruginosa NIES-843), Maer-NIES843DnaE-c (Microcystis aeruginosa NIES-843), Maer-NIES843DnaE-n (Microcystis aeruginosa NIES-843), Mau-ATCC27029GyrA (Micromonospora aurantiaca ATCC 27029), Mav-104DnaB Mycobacterium avium 104), Mav-ATCC25291DnaB (Mycobacterium avium subsp. avium ATCC 25291), Mav-ATCC35712DnaB Mycobacterium avium), Mav-PTDnaB Mycobacterium avium subsp. paratuberculosis str. k10), MboPps1 (Mycobacterium bovis subsp. bovis AF2122/97), MboRecA Mycobacterium bovis subsp. bovis AF2122/97), MboPps1 (Mycobacterium bovis subsp. bovis AF2122/97), Mbo-AF2122DnaB Mycobacterium bovis subsp. bovis AF2122/97), Mbo-1173PDnaB (Mycobacterium bovis BCG Pasteur 1173P), McaMupF (Methylococcus capsulatus Bath prophage MuMc02), McaRIR1 (Methylococcus capsulatus Bath), MchRecA (Mycobacterium chitae), Mcht-PCC7420DnaE-1 (Microcoleus chthonoplastes PCC7420), Mcht-PCC7420DnaE-2c (Microcoleus chthonoplastes PCC 7420), Mcht-PCC 7420DnaE-2n (Microcoleus chthonoplastes PCC7420), Mcht-PCC7420GyrB (Microcoleus chthonoplastes PCC7420), Mcht-PCC7420RIR1-1 (Microcoleus chthonoplastes PCC7420), Mcht-PCC7420RIR1-2 (Microcoleus chthonoplastes PCC7420), Mexhelicase (Methylobacterium extorquens AM1), MexTrbC (Methylobacterium extorquens AM1), MfaRecA (Mycobacterium fallax), MflGyrA (Mycobacterium flavescens Fla0), MflRecA (Mycobacterium flavescens Fla0), Mfl-ATCC14474RecA (Mycobacterium flavescens ATCC 14474), Mfl-PYR-GCKDnaB (Mycobacterium flavescens PYR-GCK), MgaGyrA (Mycobacterium gastri), MgaRecA (Mycobacterium gastri), MgaPps1 (Mycobacterium gastri), Mgi-PYR-GCKDnaB (Mycobacterium gilvum PYR-GCK), Mgi-PYR-GCKGyrA (Mycobacterium gilvum PYR-GCK), MgoGyrA (Mycobacterium gordonae), Min-1442DnaB (Mycobacterium intracellulare), Min-ATCC13950GyrA (Mycobacterium intracellulare ATCC 13950), MkasGyrA (Mycobacterium kansasii), Mkas-ATCC12478GyrA (Mycobacterium kansasii ATCC 12478), Mle-Br4923GyrA (Mycobacterium leprae Br4923), Mle-TNDnaB (Mycobacterium leprae strain TN), Mle-TNGyrA (Mycobacterium leprae TN), MlePps1 (Mycobacterium leprae), Mle-TNRecA (Mycobacterium leprae strain TN), MmaGyrA (Mycobacterium malmoense), MmagMagn8951BIL (Magnetospirillum magnetotacticum MS-1), MshRecA (Mycobacterium shimodei), MsmDnaB-1 (Mycobacterium smegmatis MC2 155), MsmDnaB-2 (Mycobacterium smegmatis MC2 155), Msp-KMSDnaB (Mycobacterium species KMS), Msp_KMSGyrA (Mycobacterium species KMS), Msp-MCSDnaB (Mycobacterium species MCS), Msp_MCSGyrA (Mycobacterium species MCS), MtheRecA (Mycobacterium thermoresistibile), MtuPps1 (Mycobacterium tuberculosis strain H37Rv), Mtu-CDC1551DnaB Mycobacterium tuberculosis CDC1551), Mtu-CRecA (Mycobacterium tuberculosis C), Mtu-CPHLRecA (Mycobacterium tuberculosis CPHL_A), Mtu-EAS054RecA (Mycobacterium tuberculosis EAS054), Mtu-CanettiRecA (Mycobacterium tuberculosis strain Canetti), Mtu-F11DnaB (Mycobacterium tuberculosis strain F11), Mtu-H37RaDnaB (Mycobacterium tuberculosis H37Ra), Mtu-H37RvDnaB (Mycobacterium tuberculosis H37Rv), Mtu-H37RvRecA (Mycobacterium tuberculosis H37Rv, Also CDC1551), Mtu-HaarlemDnaB (Mycobacterium tuberculosis str. Haarlem), Mtu-R604RecA-n (Mycobacterium tuberculosis 98-R604 INH-RIF-EM), Mtu-K85RecA (Mycobacterium tuberculosis K85), Mtu-So93RecA (Mycobacterium tuberculosis So93/sub_species Canetti), Mtu-T17RecA-c (Mycobacterium tuberculosis T17), Mtu-T17RecA-n (Mycobacterium tuberculosis T17), Mtu-T46RecA (Mycobacterium tuberculosis T46), Mtu-T85RecA (Mycobacterium tuberculosis T85), MvanDnaB (Mycobacterium vanbaalenii PYR-1), Mtu-T92RecA (Mycobacterium tuberculosis T92), MvanGyrA Mycobacterium vanbaalenii PYR-1), MxaRAD25 (Myxococcus xanthus DK1622), MxeGyrA (Mycobacterium xenopi strain IMM5024), Naz-0708RIR1-2 (Nostoc azollae 0708), Naz-0708RIR1-1 (Nostoc azollae 0708), NfaDnaB (Nocardia farcinica IFM 10152), NfaNfa15250 (Nocardia farcinica IFM 10152), NfaRIR1 (Nocardia farcinica IFM 10152), Nosp-CCY9414DnaE-n (Nodularia spumigena CCY9414), NpuDnaB (Nostoc punctiforme), NpuGyrB (Nostoc punctiforme), Npu-PCC73102DnaE-c (Nostoc punctiforme PCC73102), Npu-PCC73102DnaE-n (Nostoc punctiforme PCC73102), Nsp-JS614DnaB (Nocardioides species JS614), Nsp-JS614TOPRIM (Nocardioides species JS614), Nsp-PCC7120DnaB (Nostoc species PCC7120), Nsp-PCC7120DnaE-c (Nostoc species PCC7120), Nsp-PCC7120DnaE-n (Nostoc species PCC7120), Nsp-PCC7120RIR1 (Nostoc species PCC7120), OliDnaE-c (Oscillatoria limnetica str. Solar Lake), OliDnaE-n (Oscillatoria limnetica str. Solar Lake), PP-PhiELHelicase (Pseudomonas aeruginosa phage phiEL), PP-PhiELORF11 (Pseudomonas aeruginosa phage phiEL), PP-PhiELORF40 (Pseudomonas aeruginosa phage phiEL), PP-PhiELORF39 (Pseudomonas aeruginosa phage phiEL), PflFhaBIL (Pseudomonas fluorescens Pf-5), Pma-ExH1DnaE (Persephonella marina EX-H1), PlutRIR1 (Peloclictyon luteolum DSM 273), Pma-EXH1GyrA (Persephonella marina EX-H1), PnaRIR1 (Polaromonas naphthalenivorans CJ2), Posp-JS666DnaB (Polaromonas species JS666), PuncDnaB (Polynucleobacter sp. QLW-P1DMWA-1), Posp-JS666RIR1 (Polaromonas species JS666), Pssp-A1-1Fha (Pseudomonas species A1-1), PsyFha (Pseudomonas syringae pv. tomato str. DC3000), Rbr-D9GyrB (Raphicliopsis brookii D9), RceRIR1 (Rhodospirillum centenum SW), Rer-SK121DnaB (Rhodococcus erythropolis SK121), RmaDnaB (Rhodothermus marinus), Rma-DSM4252DnaE (Rhodothermus marinus DSM 4252), Rma-DSM4252DnaB (Rhodothermus marinus DSM 4252), RspRirl (Roseovarius species 217), SaP-SETP12dpol (Salmonella phage SETP12), SaP-SETP3Helicase (Salmonella phage SETP3), SaP-SETP3dpol (Salmonella phage SETP3), SaP-SETP5dpol (Salmonella phage SETP5), SareDnaB (Salinispora arenicola CNS-205), ReGHelicase (Streptomyces avermitilis MA-4680), Sel-PC6301RIR1 (Synechococcus elongatus PCC 6301), Sel-PC7942DnaE-c (Synechococcus elongatus PC7942), Sel-PC7942RIR1 (Synechococcus elongatus PC7942), Sel-PC7942DnaE-n (Synechococcus elongatus PC7942), Sel-PCC6301DnaE-n (Synechococcus elongatus PCC 6301), Sel-PCC6301DnaE-c (Synechococcus elongatus PCC 6301 and PCC7942), ShP-Sfv-2a-2457T-nPrimase (Shigella flexneri 2a str. 2457T), SepRIR1 (Staphylococcus epidermidis RP62A), ShP-Sfv-2a-301Primase (Shigella flexneri 2a str. 301), ShP-Sfv-5Primase (Shigella flexneri 5 str. 8401), SoP-SO1dpol (Sodalis phage SO-1), SruDnaB (Salinibacter ruber DSM 13855), SplDnaX (Spirulina platensis strain C1), SruPolBc (Salinibacter ruber DSM 13855), SruRIR1 (Salinibacter ruber DSM 13855), SspDnaB (Synechocystis species strain PCC6803), SspDnaE-n, DnaE-N (Synechocystis species strain PCC6803), SspDnaE-c, DnaE-C (Synechocystis species strain PCC6803), SspDnaX (Synechocystis species strain PCC6803), Ssp-JA2RIR1 (Synechococcus species JA-2-3B a 2-13), Ssp-JA2DnaB (Synechococcus species JA-2-3B a 2-13), SspGyrB (Synechocystis species strain PCC6803), Ssp-JA3DnaB (Synechococcus species JA-3-3Ab), Ssp-JA3RIR1 (Synechococcus species JA-3-3Ab), Ssp-PCC7002DnaE-c (Synechocystis species strain PCC 7002), Ssp-PCC7002DnaE-n (Synechocystis species strain PCC 7002), Ssp-PCC7335RIR1 (Synechococcus sp. PCC 7335), StP-TwortORF6 (Staphylococcus phage Twort), Susp-NBC371DnaB (Sulfurovum sp. NBC37-1), Taq-Y51MC23DnaE (Thermus aquaticus Y51MC23), TelDnaE-c (Thermosynechococcus elongatus BP-1), Tcu-DSM43183RecA (Thermomonospora curvata DSM 43183), TelDnaE-n (Thermosynechococcus elongatus BP-1), Taq-Y51MC23RIR1 (Thermus aquaticus Y51MC23), TerDnaB-1 (Trichodesmium erythraeum IMS101), TerDnaB-2 (Trichodesmium erythraeum IMS101), TerDnaE-2 (Trichodesmium erythraeum IMS101), TerDnaE-1 (Trichodesmium erythraeum IMS101), TerDnaE-3c (Trichodesmium erythraeum IMS101), TerDnaE-3n (Trichodesmium erythraeum IMS101), TerGyrB (Trichodesmium erythraeum IMS101), TerNdse-1 (Trichodesmium erythraeum IMS101), TerNdse-2 (Trichodesmium erythraeum IMS101), TerRIR-1 (Trichodesmium erythraeum IMS101), TerRIR-2 (Trichodesmium erythraeum IMS101), TerRIR-3 (Trichodesmium erythraeum IMS101), TerRIR-4 (Trichodesmium erythraeum IMS101), TerSnf2 (Trichodesmium erythraeum IMS101), TerThyX (Trichodesmium erythraeum IMS101), TfusRecA-1 (Thermobifida fusca YX), TfusRecA-2 (Thermobifida fusca YX), TfusTfu2914 (Thermobifida fusca YX), Thsp-K90RIR1 (Thioalkalivibrio sp. K90mix), Tth-DSM571RIR1 (Thermoanaerobacterium thermosaccharolyticum DSM 571), Tth-HB27DnaE-1, Tth (Thermus thermophilus EIB27), Tth-HB27DnaE-2 (Thermus thermophilus EIB27), Tth-HB27RIR1-1 (Thermus thermophilus EIB27), Tth-HB27RIR1-2 (Thermus thermophilus EIB27), Tth-HB8DnaE-1 (Thermus thermophilus HB8), Tth-HB8DnaE-2 (Thermus thermophilus HB8), Tth-HB8RIR1-1 (Thermus thermophilus HB8), Tth-HB8RIR1-2 (Thermus thermophilus HB8), TvuDnaE-c (Thermosynechococcus vulcanus), TvuDnaE-n (Thermosynechococcus vulcanus), TyeRNR-1 (Thermodesulfovibrio yellowstonii DSM 11347), TyeRNR-2 (Thermodesulfovibrio yellowstonii DSM 11347), ApeAPE0745 (Aeropyrum pernix K1), Cme-booPol-II (Candidatus Methanoregula boonei 6A8), Fac-Fer1RIR1 (Ferroplasma acidarmanus taxon:97393), FacPps1 (Ferroplasma acidarmanus), Fac-TypeIRIR1 (Ferroplasma acidarmanus type I), FacPps1 (Ferroplasma acidarmanus), HmaCDC21 (Haloarcula marismortui ATCC 43049), HmaPol-II (Haloarcula marismortui ATCC 43049), HmaPol B (Haloarcula marismortui ATCC 43049), HmaTopA (Haloarcula marismortui ATCC 43049), Hmu-DSM12286MCM (Halomicrobium mukohataei DSM 12286), Hmu-DSM12286Pol B (Halomicrobium mukohataei DSM 12286), Hsa-R1MCM (Halobacterium salinarum R-1), Hsp-NRC1CDC21 (Halobacterium species NRC-1), Hsp-NRC1Pol-II (Halobacterium salinarum NRC-1), HutMCM-2 (Halorhabdus utahensis DSM 12940), HutMCM-1 (Halorhabdus utahensis DSM 12940), HwaGyrB (Haloquadratum walsbyi DSM 16790), HvoPolB (Haloferax volcanii DS70), HwaMCM-1 (Haloquadratum walsbyi DSM 16790), HwaMCM-2 (Haloquadratum walsbyi DSM 16790), HwaMCM-3 (Haloquadratum walsbyi DSM 16790), HwaMCM-4 (Haloquadratum walsbyi DSM 16790), HwaPol-II-1 (Haloquadratum walsbyi DSM 16790), HwaPol-II-2 (Haloquadratum walsbyi DSM 16790), HwaPolB-1 (Haloquadratum walsbyi DSM 16790), HwaPolB-2 (Haloquadratum walsbyi DSM 16790), HwaPolB-3 (Haloquadratum walsbyi DSM 16790), HwaRCF (Haloquadratum walsbyi DSM 16790), HwaRIR1-1 (Haloquadratum walsbyi DSM 16790), HwaRIR1-2 (Haloquadratum walsbyi DSM 16790), HwaTop6B (Haloquadratum walsbyi DSM 16790), rPol-II-1 (Haloquadratum walsbyi DSM 16790), MaeoPol-II (Methanococcus aeolicus Nankai-3), MaeoRFC (Methanococcus aeolicus Nankai-3), MaeoRNR (Methanococcus aeolicus Nankai-3), Maeo-N3Helicase (Methanococcus aeolicus Nankai-3), UDPGD (Methanococcus aeolicus Nankai-3), Maeo-N3RtcB (Methanococcus aeolicus Nankai-3), Mein-MEPEP (Methanocaldococcus infernus ME), Mein-MERFC (Methanocaldococcus infernus ME), MemarMCM2 (Methanoculleus marisnigri JR1), MemarPol-II (Methanoculleus marisnigri J1-1), Mesp-FS406Pol B-1 (Methanocaldococcus sp. FS406-22), Mesp-FS406Pol B-2 (Methanocaldococcus sp. FS406-22), Mesp-FS406Pol B-3 (Methanocaldococcus sp. FS406-22), Msp-FS406-22LHR (Methanocaldococcus sp. FS406-22), Mfe-AG86Pol-1 (Methanocaldococcus fervens AG86), Mfe-AG86Pol-2 (Methanocaldococcus fervens AG86), MhuPol-II (Methanospirillum hungateii JF-1), MjaGF-6P (Methanococcus jannaschii), MjaHelicase (Methanococcus jannaschii), MjaHyp-1 (Methanococcus jannaschii), Mj aIF2 (Methanococcus jannaschii), Mj aKlb a (Methanococcus jannaschii), MjaPEP (Methanococcus jannaschii), MjaPol-1 (Methanococcus jannaschii), MjaPol-2 (Methanococcus jannaschii), MjaRFC-1 (Methanococcus jannaschii), MjaRFC-2 (Methanococcus jannaschii), MjaRFC-3 (Methanococcus jannaschii), MjaRNR-1 (Methanococcus jannaschii), MjaRNR-(Methanococcus jannaschii), MjaHyp-2 (Methanococcus jannaschii), MjaTFIIB (Methanococcus jannaschii), UDPGD (Methanococcus jannaschii), Mjar-Gyr (Methanococcus jannaschii), rPolA′ (Methanococcus jannaschii), Mja rPol A′ (Methanococcus jannaschii), MkaCDC48 (Methanopyrus kandleri AV19), MkaEF2 (Methanopyrus kandleri AV19), MkaRFC (Methanopyrus kandleri AV19), MkaRtcB (Methanopyrus kandleri AV19), MkaVatB (Methanopyrus kandleri AV19), MthRIR1 (Methanothermobacter therm autotrophicus), Mvu-M7Helicase (Methanocaldococcus vulcanius M7), Mvu-M7Pol-1 (Methanocaldococcus vulcanius M7), Mvu-M7Pol-2 (Methanocaldococcus vulcanius M7), Mvu-M7Pol-3 (Methanocaldococcus vulcanius M7), UDPGD (Methanocaldococcus vulcanius M7), NeqPol-c (Nanoarchaeum equitans Kin4-M), NeqPol-n (Nanoarchaeum equitans Kin4-M), Nma-ATCC43099MCM (Natrialba magadii ATCC 43099), Nma-ATCC43099PolB-1 (Natrialba magadii ATCC 43099), Nma-ATCC43099PolB-2 (Natrialba magadii ATCC 43099), NphCDC21 (Natronomonas pharaonis DSM 2160), NphPolB-2 (Natronomonas pharaonis DSM 2160), NphPolB-1 (Natronomonas pharaonis DSM 2160), rPolA″ (Natronomonas pharaonis DSM 2160), PabCDC21-1 (Pyrococcus abyssi), PabCDC21-2 (Pyrococcus abyssi), PabIF2 (Pyrococcus abyssi), PabKlbA (Pyrococcus abyssi), PabLon (Pyrococcus abyssi), PabMoaa (Pyrococcus abyssi), PabPol-II (Pyrococcus abyssi), PabRFC-1 (Pyrococcus abyssi), PabRFC-2 (Pyrococcus abyssi), PabRIR1-1 (Pyrococcus abyssi), PabRIR1-2 (Pyrococcus abyssi), PabRIR1-3 (Pyrococcus abyssi), PabHyp-2 (Pyrococcus abyssi), PabVMA (Pyrococcus abyssi), ParRIRl (Pyrobaculum arsenaticum DSM 13514), PfuCDC21 (Pyrococcus furiosus), PfuIF2 (Pyrococcus furiosus), PfuKlbA (Pyrococcus furiosus), PfuLon (Pyrococcus furiosus), PfuRFC (Pyrococcus furiosus), PfuRIR1-1 (Pyrococcus furiosus), PfuRIR1-2 (Pyrococcus furiosus), PfuHyp-2 (Pyrococcus furiosus), PfuTopA (Pyrococcus furiosus), PfuVMA (Pyrococcus furiosus), PhoCDC21-1 (Pyrococcus horikoshii OT3), PhoCDC21-2 (Pyrococcus horikoshii OT3), PhoIF2 (Pyrococcus horikoshii OT3), PhoKlbA (Pyrococcus horikoshii OT3), PhoLHR (Pyrococcus horikoshii OT3), PhoLon (Pyrococcus horikoshii OT3), PolI (Pyrococcus horikoshii OT3), PhoPol-II (Pyrococcus horikoshii OT3), PhoRFC (Pyrococcus horikoshii OT3), PhoRIR1 (Pyrococcus horikoshii OT3), PhoRadA (Pyrococcus horikoshii OT3), PhoVMA (Pyrococcus horikoshii OT3), PhoHyp-2 (Pyrococcus horikoshii OT3), Phor-Gyr (Pyrococcus horikoshii OT3), Psp-GBDPol (Pyrococcus species GB-D), Smar1471 (Staphylothermus marinus F1), PhoVMA (Picrophilus torridus DSM 9790), Tac-ATCC25905VMA (Thermoplasma acidophilum ATCC 25905), SmarMCM2 (Staphylothermus marinus F1), Tac-DSM1728VMA (Thermoplasma acidophilum DSM1728), Tsp-TYPol-1 (Thermococcus aggregans), Tsp-TYPol-2 (Thermococcus aggregans), Tsp-TYPol-3 (Thermococcus aggregans), TbaPol-II (Thermococcus barophilus MP), TfuPol-1 (Thermococcus fumicolans), ThyPol-1 (Thermococcus hydrothermalis), TfuPol-2 (Thermococcus fumicolans), ThyPol-2 (Thermococcus hydrothermalis), TkoCDC21-1 (Thermococcus kodakaraensis KOD1), TkoCDC21-2 (Thermococcus kodakaraensis KOD1), TkoHelicase (Thermococcus kodakaraensis KOD1), TkoIF2 (Thermococcus kodakaraensis KOD1), TkoKlbA (Thermococcus kodakaraensis KOD1), TkoLHR (Thermococcus kodakaraensis KOD1), Psp-KODPol-1 (Thermococcus kodakaraensis KOD1), KODPol-2 (Thermococcus kodakaraensis KOD1), TkoPol-II (Thermococcus kodakaraensis KOD1), TkoRIR1-1 (Thermococcus kodakaraensis KOD1), TkoRFC (Thermococcus kodakaraensis KOD1), TkoRIR1-2 (Thermococcus kodakaraensis KOD1), TkoRadA (Thermococcus kodakaraensis KOD1), TkoTopA (Thermococcus kodakaraensis KOD1), Tkor-Gyr (Thermococcus kodakaraensis KOD1), T1iPol-1 (Thermococcus litoralis), T1iPol-2 (Thermococcus litoralis), TmaPol (Thermococcus marinus), Ton-NA1LHR (Thermococcus onnurineus NA1), Ton-NA1Pol (Thermococcus onnurineus NA1), TpePol (Thermococcus peptonophilus strain SM2), Tsi-MM739Lon (Thermococcus sibiricus MM 739), Tsi-MM739Pol-1 (Thermococcus sibiricus MM 739), Tsi-MM739Pol-2 (Thermococcus sibiricus MM 739), Tsi-MM739RFC (Thermococcus sibiricus MM 739), AM4RtcB (Thermococcus sp. AM4), Tsp-AM4LHR (Thermococcus sp. AM4), Tsp-AM4Lon (Thermococcus sp. AM4), Tsp-AM4RIR1 (Thermococcus sp. AM4), Tsp-GE8Pol-2 (Thermococcus species GE8), Tsp-GE8Pol-1 (Thermococcus species GE8), Tsp-GTPol-1 (Thermococcus species GT), Tsp-GTPol-2 (Thermococcus species GT), Tsp-OGL-P20Pol (Thermococcus sp. OGL-20P), TthiPol (Thermococcus thioreducens), TziPol (Thermococcus zilligii), TvoVMA (Thermoplasma volcanium GSS1), Unc-ERSPFL (uncultured archaeon GZfos13E1), Unc-ERSRIR1 (uncultured archaeon GZfos9C4), Unc-MetRFSMCM2 (uncultured archaeon Rice Cluster I), or Unc-ERSRNR (uncultured archaeon GZfos10C7).

An intein name provides information about the organism and the protein name given to a homolog of the protein that hosts the intein in a well-studied organism. For example, in the name Ade-ER3PRP8, “Ade-ER3” refers to the organism Ajellomyces dermatitidis ER-3 and PRP8 is the protein name given to a homolog of the protein that hosts the intein in a well-studied organism.

The intein may have a sequence of one the inteins disclosed in any one of U.S. pre-grant patent application publication Nos. U.S. 2013-0007919 (published on Jan. 3, 2013 from U.S. application Ser. No. 13/508,156, filed Sep. 20, 2012), Nos. U.S. 2013-0036517 (published on Feb. 7, 2013 from U.S. application Ser. No. 13/508,234, filed Sep. 20, 2012), and U.S. 2013-0071884 (published on Mar. 21, 2013 from U.S. application Ser. No. 13/508,280, filed Sep. 20, 2012), all of which are incorporated by reference herein as if fully set forth.

The intein may be a trans-splicing intein. The trans-splicing intein may be gp41-1, Cbu_DnaB, Mja_GF-6P, Mja_Hyp-1, Mja_IF2, Mja_Pol-1, Pab_CDC21-1, Pab_IF2-N, Pab_VMA, Pho_IF2, Pho_VMA, Rma_DnaB, Sru_DnaB, Tag_Pol-1_Tsp-TY_Pol-1, Ter_RIR1-4, Tko_IF2, or Tth-HB27 DnaE-2 intein. The intein may be gp41-1 intein. The gp41-1 intein may comprise, consist essentialy of, or consist of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 11.

The trans-splicing intein may comprise two parts. One part of the trans-splicing intein may be the N-terminal intein, or N-intein (I^(N)). Another part of the trans-splicing intein may be the C-terminal intein, or C-intein (I^(C)). The trans-splicing intein may comprise a combination of N-intein and C-intein as set forth in Table I, below. The N-intein and C-intein sequences listed in the same row as one trans-splicing intein indicate the sequences of the N-intein and C-intein in the first precursor and second precursor, respectively. In each of the trans-splicing inteins of Table I, the N-intein comprise, consist essentially of, or consist of an amino acid sequence having at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to the sequence identified on the same row as the respective intein in Table 1. Similarly, in each of the trans-splicing inteins of Table I, the C-intein may comprise, consist essentially of, or consist of an amino acid sequence having at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to the sequence identified on the same row as the respective intein in Table 1. For example, in the trans-splicing intein listed as A, the N-intein may comprise at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 14, and the C-intein may comprise at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 15.

Trans- Splicing Intein N-intein C-intein A SEQ ID NO: 14 SEQ ID NO: 15 B SEQ ID NO: 16 SEQ ID NO: 17 C SEQ ID NO: 18 SEQ ID NO: 19 D SEQ ID NO: 20 SEQ ID NO: 21 E SEQ ID NO: 22 SEQ ID NO: 23 F SEQ ID NO: 24 SEQ ID NO: 25 G SEQ ID NO: 26 SEQ ID NO: 27 H SEQ ID NO: 28 SEQ ID NO: 29 I SEQ ID NO: 30 SEQ ID NO: 31 J SEQ ID NO: 32 SEQ ID NO: 33 K SEQ ID NO: 34 SEQ ID NO: 35 L SEQ ID NO: 36 SEQ ID NO: 37 M SEQ ID NO: 38 SEQ ID NO: 39 N SEQ ID NO: 40 SEQ ID NO: 41 O SEQ ID NO: 42 SEQ ID NO: 43 P SEQ ID NO: 44 SEQ ID NO: 45 Q SEQ ID NO: 46 SEQ ID NO: 47

When each of the N-inteins and C-inteins in Table 1 are at 100% identity to the indicated sequence, the trans-splicing inteins are as follows: intein a is gp41-1, intein B is Cbu_DnaB, intein C is Mja_GF-6P, intein D is Mja_Hyp-1, intein E is Mja_IF2, intein F is Mja_Pol-1, intein G is Pab_CDC21-1, intein H is Pab_IF2-N, intein I is Pab_VMA, intein J is Ph0_IF2, intein K is Pho_VMA, intein L is Rma_DnaB, intein M is Sru_DnaB, intein N is Tag_Pol-1 Tsp-TY_Pol-1, intein 0 is Ter_RIR1-4, intein P is Tko_IF2 and intein Q is Tth-HB27 DnaE-2. At less than 100% identity, each N-intein: C intein pair forms a variant of the respective gp41-1, Cbu_DnaB, Mja_GF-6P, Mja_Hyp-1, Mja_IF2, Mja_Pol-1, Pab_CDC21-1, Pab_IF2-N, Pab_VMA, iPh0_IF2, Pho_VMA, Rma_DnaB, Sru_DnaB, Tag_Pol-1 Tsp-TY_Pol-1, Ter_RIR1-4, Tko_IF2 and Tth-HB27 DnaE-2 inteins. The variant retains trans-splicing activity, which can be tested using bi-cistronic expression cassettes for restoration of protease activity described in Example 18.

As used herein, the term iProtease is an alternative name for an intein-modified protease. The first precursor may be referred to as an “NI,” which may be an in frame fusion of 1) the protease N-terminal fragment (N-extein), to 2) the N-terminal part of the trans-splicing intein (I^(N)). The second precursor may be referred to as an “IC,” which may be an in frame fusion of 1) the C-terminal part of the trans-splicing intein (I^(C)) to 2) the C-terminal fragment (C-extein) of the protease. The product of splicing may have the amino extein (N) and carboxy extein (C) seamlessly joined by a peptide bond and may be called “NC.” The NC may be the target protease obtained by trans-splicing. If the N-extein comprised a pre-domain, auto-cleavage of the pro-domain after splicing may result in the active target protease. “(NI+IC) premix” refers to a mix of splicing components NI and IC in an inactive state that may have no protease activity but may be induced by dilution to splice and yield the fully active target protease.

In an embodiment, the NI and IC precursors may be solubility optimized versions of the prototype molecules iSavinase:S317-Gp41-1 NI (SEQ ID NO: 49) and IC (SEQ ID NO: 50). These precursors were described in PCT application PCT/US2013/063304, which was filed Oct. 3, 2013 and published on Apr. 4, 2014 as International Publication No. WO2014/055782, which is incorporated herein by reference as if fully set forth.

An intein-modified protease may include intein-modified protease components optimized for improved solubility. The optimized intein-modified protease components may have optimizations restricted only to intein parts to ensure splicing leaves the sequence of the target enzyme unchanged when the intein removes itself and seamlessly joins the flanking protein sequences with a peptide bond. Splicing may restore the intact protein to full protease activity. The first precursor of an intein-modified protease may comprise, consist essentially of, or consist of an amino acid sequence with at least at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 1. The second precursor of an intein-modified protease may comprise, consist essentially of, or consist of an amino acid sequence with at least at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 2.

FIG. 1 shows schematic drawings of the solubility optimized molecules. Referring to FIG. 1, Savinase may be split between catalytic residues to Sav-N and Say-C. Referring to FIG. 1, catalytic residues may be: D (Asp143), H (His172), and S (Ser326). The relative positions of these residues are marked by vertical lines. Intein parts I^(N) and I^(C) may be attached to Savinase parts Sav-N and Sav-C, respectively. Solubility engineering may be restricted to the intein parts. Solubility enhancer Trx domains may be attached to each intein part via a DPNG (Asp-Pro-Asn-Gly; SEQ ID NO: 5) linker. The C-intein part (I^(C)) may have multiple mutations for enhanced solubility. These may be M894, L91T, L95T, L122G (numbering is by the position in the fused I^(N)+I^(C)).

Solubility optimized NI, termed NI-DPNG-Trx, may have a C-terminal solubility enhancer thioredoxin domain (SEQ ID NO: 51) fused via an Asp-Pro-Asn-Gly (DPNG; SEQ ID NO: 5) linker to the C-terminal end of the Gp41-1 N-intein (I^(N); SEQ ID NO: 14) in the iProtease:S317-Gp41-1N. In the solubility optimized I^(C), termed Trx-DPNG-MTT I^(C)[G122L], the thioredoxin domain (SEQ ID NO: 5) is fused via an Asp-Pro-Asn-Gly (DPNG; SEQ ID NO: 5) linker N-terminal to the mutated C-intein (I^(C); SEQ ID NO: 15) of the iProtease:S317-Gp41-1C. The Trx in the NI (termed Trx-1) is nine aa residue longer at the C-terminus than the Trx in the I^(C) (termed Trx-2). The mutated C-intein (SEQ ID NO: 15), MTT-IC[L122G] may have four solubility enhancer mutations at positions 89, 91, 95, and 122 as follows: M894, L91T, L95T and L122G (numbering is by the position in the fused I^(N)+I^(C) of GP41-1).

In an embodiment, the intein may be fused to the target protease in such a position as to substantially reduce or inhibit the activity of the target protease. In other words, the fragments of the protease included in the first precursor and the second precursor have no or substantially reduced protease activity in comparison to the intact target protease. The substantially reduced activity may be 40% to 35%, 35% to 30%, 30% to 25%, 25% to 20%, 20% to 15%, 15% to 10%, 10% to 5%, 5% to 1%, 1% to 0.5% of the activity of the intact target protease, or any value in a range between any two of the foregoing (endpoints inclusive). The activity of the target protease may be restored upon splicing of the intein. Activity may be analyzed by a Savinase enzyme assay outlined in Example 2.

An embodiment comprises a composition comprising the precursors (NI and IC) of any intein-modified protease herein. The first precursor NI may comprise, consist essentially of, or consists of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to a reference sequence of SEQ ID NO: 1. The first precursor may be capable of trans-splicing with the second precursor to form the target protease. The second precursor IC may comprise, consist essentially of, or consist of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to a reference sequence of SEQ ID NO: 2. The second precursor may be capable of trans-splicing with the first precursor to form the target protease. The concentration of the first precursor or the second precursor may be in a range from 0.01% (v:v) to 10% (v:v). The concentration may be 0.02% (v:v), 0.03% (v:v), 0.04% (v:v), 0.05% (v:v), 0.06% (v:v), 0.07% (v:v), 0.08% (v:v), 0.09% (v:v), 0.1% (v:v), 0.2% (v:v), 0.3% (v:v), 0.4% (v:v), 0.5% (v:v), 0.6% (v:v), 0.7% (v:v), 0.8% (v:v), 1.0% (v:v), 2.0% (v:v), 3.0% (v:v), 4.0% (v:v), 5.0% (v:v), 6.0% (v:v), 7.0% (v:v), 8.0% (v:v), 9.0% (v:v), or 10.0% (v:v), or any value between any two of the foregoing concentration points. The concentration of the first precursor or the second precursor may be in a range from 0.3% (v:v) to 4% (v:v). The concentration may be 0.3% (v:v), 0.4% (v:v), 0.5% (v:v), 0.6% (v:v), 0.7% (v:v), 0.8% (v:v), 1.0% (v:v), 2.0% (v:v), 3.0% (v:v), or 4.0% (v:v), or any value between any two of the foregoing concentration points. The concentration of the first precursor or the second precursor may be at least 0.3% (v:v), at least 0.4% (v:v), at least 0.5% (v:v), at least 0.6% (v:v), at least 0.7% (v:v), at least 0.8% (v:v), at least 1.0% (v:v), at least 2.0% (v:v), at least 3.0% (v:v), or at least 4.0% (v:v), or at least any value between any two of the foregoing concentration points. As used above, the concentration 10% (v:v) corresponds to a concentration of 381.00 μM, 5% (v:v) corresponds to a concentration of 190.50 μM, 1% (v:v) corresponds to a concentration of 38.1 μM, 0.50% (v:v) corresponds to 19.05 μM, and 0.1% (v:v) corresponds to 3.81 μM.

The composition may further comprise at least one or more of effectors, components of a home care product or other ingredients. The one or more effectors may comprise one or more of sodium salt supplements, potassium salt supplements, ammonium salt supplements, charged polymeric salt supplements, polyol supplements, sodium chloride, tetrasodium iminodisuccinate, disodium succinate, disodium tartrate, potassium lactate, potassium citrate, potassium chloride, sodium nicotinate, ammonium sulfate, ammonium nitrate, lithium citrate, sodium polyaspartate, sodium polyacrylate, tetraethylene glycol, polyethylene glycol, tetraglycol, propylene carbonate, mono propylene glycol, glycerol, and tomadol. The potassium chloride concentration may be in a range from 0.1 M to 5.0 M. The concentration may be 0.1 M, 0.2 M, 0.3 M, 0.4 M, 0.5 M, 0.6 M, 0.7 M, 0.8 M, 0.9 M, 1.0 M, 1.1 M, 1.2 M, 1.3M, 1.4M, 1.5 M, 1.6 M, 1.7 M, 1.8 M, 1.9 M, 2.0 M, 2.1 M, 2.2 M, 2.3 M, 2.4 M, 2.5 M, 2.6 M, 2.7 M, 2.8 M, 2.9 M, 3.0 M, 3.1 M, 3.2 M, 3.3 M, 3.4 M, 3.5 M, 3.6 M, 3.7 M, 3.8 M, 3.9 M, 4.0 M, 4.1 M, 4.2 M, 4.3 M, 4.4 M, 4.5 M, 4.6 M, 4.7 M, 4.8 M, 4.9, 5.0 M, or any value between any two of the foregoing concentration points. The potassium chloride concentration may be in a range from 0.5 M to 2.0 M. The concentration may be 0.5 M, 0.6 M, 0.7 M, 0.8 M, 0.9 M, 1.0 M, 1.1 M, 1.2 M, 1.3M, 1.4M, 1.5 M, 1.6 M, 1.7 M, 1.8 M, 1.9 M, 2.0 M, 0.5 M, 0.6 M, 0.7 M, 0.8 M, 0.9 M, 1.0 M, 1.1 M, 1.2 M, 1.3M, 1.4M, 1.5 M, 1.6 M, 1.7 M, 1.8 M, 1.9 M, 2.0 M, or any value between any two of the foregoing concentration points. The concentrations of any one of the effectors listed herein may be the same or similar to the concentrations of the potassium chloride described.

The components of a composition or home care product herein may comprise at least one of a detergent, a soap, an industrial cleaner or a dishwashing liquid.

The detergent in a composition, home care product, or method herein may be any detergent. The detergent may be any commercially available detergent. The detergent may be but is not limited to GRESINOL™ SEVENTH GENERATION™, MYERS™, TIDE™, DREFT™, PUREX™ BIOKLEEN™, SUN AND EARTH™, GAIN™, ALL™, WOOLITE™, XTRA™, FAB™, SNUGGLE™, CHEER™, WISK™, SURF™, OMO™, PERSIL™ BREEZE™, SKIP™, ALA™, RINSO™ or GREENSHIELD™. The soap may be any soap. The soap may be any commercially available soap. The soap may be but is not limited to IVORY™, DIAL™, DOVE™, SOFTSOAP™, METHOD™, KLEENEX™, or CAREX™.

The industrial cleaner may be any industrial cleaner. The industrial cleaner may be any commercially available industrial cleaner. The industrial cleaner may be but is not limited to ELIMINATOR™ (caustic additive), ALKAZOLV™, ULTRAZOLV™ 700, CONCEPT™ C20, PERFORM™, or REFLEX™ B165. The industrial cleaner may be but is not limited to Caustic, NaOH (1%), EDTA, sodium hypochlorite, or nitric acid (1%).

The dishwashing liquid may be any dishwashing liquid. The dishwashing liquid may be any commercially available dishwashing liquid. The dishwashing liquid may be but is not limited to CASCADE™ JOY™ PALMOLIVE™, GAIN™, GLO™ DAWN™, GREEN WORKS™ ULTRA™, ZIP™ CLOROX™, TRIM™, or TAJ™.

The detergent concentration may be in a range from 40% (v:v) to 100% (v:v). The concentration may be 40% (v:v), 45% (v:v), 50% (v:v), 55% (v:v), 60% (v:v), 65% (v:v), 70% (v:v), 75% (v:v), 80% (v:v), 90% (v:v), 91% (v:v), 92% (v:v), 93% (v:v), 94% (v:v), 95% (v:v), 96% (v:v), 97% (v:v), 98% (v:v), 99% (v:v), or 100% (v:v) or any value between any two of the foregoing concentration points. The detergent concentration may be in a range from 65% to 100%. The concentration may be 65% (v:v), 70% (v:v), 75% (v:v), 80% (v:v), 90% (v:v), 91% (v:v), 92% (v:v), 93% (v:v), 94% (v:v), 95% (v:v), 96% (v:v), 97% (v:v), 98% (v:v), 99% (v:v), or 100% (v:v), or any value between any two of the foregoing concentration points. The concentrations of any one of the soaps, industrial cleaners, or dishwashing liquids listed herein may be similar to the concentrations of the detergent. The percent detergent listed here refers to the percent of stock detergent in comparison to the final volume of the home care product or composition.

The components of the home care product, or a composition herein, may further comprise at least one ingredient selected from the group consisting of: water softeners, surfactants, bleach, enzymes, brighteners, fragrances, anionic surfactants, nonionic surfactants, builders to remove the hardness ions, antiredeposition agents, dye transfer inhibitors, soil release polymers, optical brighteners, enzyme stabilizers, viscosity control compounds, pH control compounds, soap and silicones to control excessive foaming, preservatives for microbial control, perfume and dye for scent and appearance, bleaching agents, water, solubilizers, alkylbenzenesulphonates, ethoxylated fatty alcohols, sodium citrate, tetrasodium EDTA or an acrylic polymer, PVP K-30, Chromabond S-100, Chromabond S-400, Sorez 100, Repel-O-Tex SRP-6, Tinopal CBS-X, calcium chloride, sodium tetraborate, propylene glycol, sodium formate, sodium citrate, monoethanolamine, propylene glycol, sodium xylene sulfonate, polymers, and citric acid. The composition may further comprise a detergent as a fuel additive. The fuel additive may be a long-chain amine or amide. The fuel additive may be a polyisobuteneamine or polyisobuteneamide/succinimide. The composition may comprise a detergent as a biological reagent. The biological reagent may be used for isolation and purification of integral membrane proteins found in biological cells. The concentrations of any one of the additional ingredients listed herein may be any concentrations known in the art.

In an embodiment, the composition may comprise 0.5% (v:v) of the first precursor, 0.5% (v:v) of the second precursor, 1M KCl and variable concentrations of detergent. The variable concentrations of the detergent may be in a range from 65% (v:v) to 100% (v:v). The composition may comprise 38.104 of each of the first precursor and the second precursor, 1M KCl and variable concentrations of detergent.

The following exemplary detergent formulations may be a detergent added as a stock detergent to a composition or home product herein to a desired concentration, or provided in a method herein. An exemplary detergent formulation may include Aduxol, castor oil ethoxylate, fatty alcohol, ethoxylate, polyethylene glycol, alkoxylated carboxylic acid, glycerol, Neodol, MPG, TEA, MEA, PRIFAC™ 5908, LAS acid, citric acid, sodium sulfite, SOKALAN HP20, SLES 3EO, DEQUEST™ 2010 and deionized water. Further exemplary detergents may be found in U.S. Pat. No. 4,115,292, Richardson et al., filed as U.S. application Ser. No. 05/789,325 on Apr. 20, 1977 and issued on Sep. 19, 1973; U.S. Pat. No. 3,717,630, Booth, issued on Feb. 20, 1967; U.S. Pat. No. 3,332,880, Kessler et al., issued on Jul. 25, 1967, all of which are both of which are incorporated herein by reference. An exemlpary type of anionic surfactant may be found in U.S. Pat. No. 3,941,710, Gilbert et al., issued. Mar. 2, 1976, which is incorporated. herein by reference as if fully set forth. An exemplary listing of classes and species of nonionic surfactants useful herein may be found in U.S. Pat. No. 3,664,961, Norris, issued on Mar. 23, 1972, which is incorporated herein by reference as if fully set forth.

An exemplary formulation of a liquid laundry detergent enhanced with natural essence and further comprising non-petroleum source anionic and nonionic surfactants, naturally occurring builders is disclosed in U.S. Pat. No. 7,648,953, Bastigket et al., filed on May 8, 2008 as U.S. application Ser. No. 12/151,597 and issued Jan. 19, 2010, which is incorporated herein by reference as if fully set forth. The formulation disclosed in this patent includes the following ingredients: surfactant mixture consisting of: about 1% to about 20% by weight of an alkyl ether sulfate of the general formula R—(OCH₂CH₂)_(x)—O—SO₃M, where R is a non-petroleum derived fatty alcohol with even number carbon chain lengths of from about C₈ to about C₂₀, and where x is from about 0.5 to about 8, and where M is an alkali metal or ammonium cation; from about 1% to about 10% by weight of a fatty alcohol ethoxylate of general formula R—(OCH₂CH₂)_(x)—OH, where R is a non-petroleum derived fatty alcohol with even number carbon chain lengths of from about C₁₀ to about C₁₈, and where x is from about 0.5 to about 9; and optionally from about 1% to about 10% by weight of a fatty acid soap; from about 0.1% to about 5% of a natural essence; from about 0.1% to about 10% by weight of a builder; and water.

An exemplary formulation of liquid laundry detergent compositions that includes anionic surfactant, fabric care agent, cationic deposition aid and performance booster are disclosed in European Publication No. EP2126017 A1, Panandiker et al, filed. Feb. 12, 2009, which is incorporated herein by reference as if fully set, forth. The performance booster in this formulation is chosen such that it will not react with the cationic deposition aid or fabric care agent, to form a coacervate and/or to precipitate from solution. The liquid laundry detergent formulation comprises by weight percentage of said composition: a. from 1% to 80% of anionic surfactant; b. from 0.1% to 10% of fabric care agent; c. from 0.01% to 2% of deposition aid; and d. from 0.05% to 10% of performance booster selected from enzymes, anionic polymers, and brighteners. The anionic surfactant is selected from the group of: C₈-C₂₂ fatty acid or its salts; Cn-Ci₈ alkyl benzene sulfonates; C₁0-C₂0 branched-chain and random alkyl sulfates; C₁₀-C₁₈ alkyl alkoxy sulfates, wherein x is from 1-30; mid-chain branched alkyl sulfates; mid-chain branched alkyl alkoxy sulfates; Ci₀-Ci₈ alkyl alkoxy carboxylates comprising 1-5 ethoxy units; modified alkylbenzene sulfonate; C₁₂-C₂₀ methyl ester sulfonate; Ci₀-Ci₈ alpha-olefin sulfonate; C₆-C₂₀sulfosuccinates; and combinations thereof. The fabric care agent provides fabric care benefits selected from the group of: fabric softening; color protection; color restoration; pill/fuzz reduction; anti-abrasion; anti-wrinkling; and combinations thereof. The fabric care agent is selected from the group of: silicone derivates; oily sugar derivatives; dispersible polyolefins; polymer latexes; cationic surfactants; and combinations thereof. Enzyme is selected from the group of: proteases; amylases; lipases; cellulases; carbohydrase; xyloglucanase; mannanase; pectate lyase; and combinations thereof. Performance booster is a brightener preferably selected from the group of: disodium 4,4′-bis-(2-sulfostyryl) biphenyl; benzenesulfonic acid; 2,2′-(1,2-ethenecliyl)bis[5-[4-[(2-hydroxyethyl)methylamino]-6-(phenylamino)-1,3,5-triazin-2-y]amino]-, disodium salt; disodium 4,4′-bis{[4-anilino-6-[bis(2-hydroxyethyl)amino-s-triazin-2yl]-amino}-2,2′-stilbenedisulfonate; disodium 4,4′-bis[(4-anilino-6-(N-2-hydroxyethyl-N-m ethylamino)-s-triazine-2-yl)amino]2,2′-stilbenedisulfonate; disodium 4,4′-bis{[4-anilino-6-methylamino-s-triazin-2-yl]-amino}-2,2′-stilbenedisulfonate; disodium 4,4″-bis[4,6-di-anilino-s-triazin-2-yl]-2,2′-stilbenedisulfonate; disodium 4, 4′-bis{[4-anilino-6-morpholino-s-triazin-2-yl}-amino}-2,2′-stilbenedisulfonate; and combinations thereof. Performance booster is an anionic dispersant polymer. The composition may further comprise a pearlescent agent preferably selected from the group of: mica; bismuth oxychloride; fish scales; mono and diesters of alkylene glycol. Pearlescent agent may be selected from the group of: mica; ethylene glycol distearate; ethylene glycolmonostearate; bismuth oxychloride; and combinations thereof. The composition may further comprise laundry adjuncts selected from the group of: nonionic surfactant; builder; polymeric soil release agent; and combinations thereof.

Exemplary detergent formulations may be found in International Publication No. WO2014019903, Carswel et al., published Feb. 6, 2014, which is incorporated herein by reference as if fully set forth. This application discloses an alkaline liquid laundry detergent comprising at least 1 wt % triethanolamine, at least 5 wt % non-soap surfactant and at least 0.5 wt % of a polyester according to the following formula (I) wherein R1 and R2 independently of one another are X—(OC2H4)n-(OC3H6)m wherein X is C₁₋₄ alkyl, the —(OC2H4) groups and the —(OC3H6) groups are arranged blockwise and the block consisting of the —(OC3H6) groups is bound to a COO group or are HO—(C3H6), n is based on a molar average a number of from 12 to 120, preferably 40 to 50, m is based on a molar average a number of from 1 to 10, and a is based on a molar average a number of from 4 to 9.

Exemplary detergent formulations may be found in International Publication No. WO02013160023, Best et al., published Oct. 31, 2013, which is incorporated herein by reference as if fully set forth. This application discloses an externally structured aqueous isotropic liquid laundry detergent composition comprising: at least 10 wt % water, at least 10 wt % of a mixed surfactant system comprising anionic surfactant, an external structuring system comprising from 0.025 to 0.15 wt % insoluble cellulosic fibre comprising at least 50 wt % activated citrus fibre, —at least 0.01 wt % suspended non-clay solid particles, characterised in that the external structuring system further comprises at least 0.1 wt % water-swellable clay.

Exemplary detergent formulations may be found in U.S. Pat. No. 5,731,278, Nair at al., filed on Oct. 29, 1996 and issued on Mar. 24, 1998, which is incorporated herein by reference as if fully set forth. This reference discloses a liquid laundry detergent that contains a surfactant component, a formate thickener component, a selected perfume component and a relatively large amount of an aqueous liquid carrier.

Exemplary detergent formulations may be found in International Publication No. WO1999049009, Depoot et al., published Sep. 30, 1999, which is incorporated herein by reference as if fully set forth. This application discloses a liquid laundry detergent comprising HEDP, and water soluble and/or dispersible, modified polyamines having functionalized backbone moieties which provide a stabilizing effect.

Exemplary detergent formulations may be found in International Publication No. WO1998013461, McIver et al., published on Apr. 2, 1998, which is incorporated herein by reference as if fully set forth. This application discloses a liquid laundry detergent comprising one or more of the following: suds boosters, builders, soil release polymers, polyacrylate polymers, dispersing agents, dye transfer inhibitors, dyes, perfumes, processing aids, brighteners, and mixtures thereof.

Exemplary detergent formulations may be found in European Publication No. EP0929642, McIver et al. published on Jul. 21, 1999, which is incorporated herein by reference as if fully set forth. This application disclsoses a liquid laundry detergent comprising one or more of the following: suds boosters, builders, soil release polymers, polyacrylate polymers, dispersing agents, dye transfer inhibitors, dyes, perfumes, processing aids, brighteners, and mixtures thereof.

Exemplary liquid laundry detergent formulations containing anionic surfactants may be found in European Publication No. EP2551335, Souter et al., published Jan. 1, 2013, which is incorporated herein by reference as if fully set forth.

Exemplary detergent formulations may be found in International Publication No. WO2014190131, Frankenbach et al., published Nov. 27, 2014, which is incorporated herein by reference as if fully set forth. This application discloses a liquid laundry detergent comprising branched surfactants

Exemplary detergent formulations may be found in European Publication No. EP2712913, Guida et al, published Apr. 2, 2014, which is incorporated herein by reference as if fully set forth. This publication discloses a liquid laundry detergent comprising crystallized triglycerides including crystallized hydrogenated castor oil (HCO), surfactant and organic non-aminofunctional alcohols.

Exemplary detergent formulations may be found in Chinese Publication No. CN103242973, Zhu et al., published Aug. 14, 2014, which is incorporated herein by reference as if fully set forth. This application discloses a liquid laundry detergent comprising 0.02-15% of cationic softener, 0.01-10% of modified silicon oil, 2-50% of nonionic surfactant.

Exemplary detergent formulations may be found in European Publication No. EP2855408, Ellison et al., published Apr. 8, 2015, which is incorporated herein by reference as if fully set forth. This publication discloses a liquid laundry detergent made by dimerizing one or more even numbered alpha olefins to produce one or more vinylidenes; hydroformylating the vinylidene(s) to produce a mixture of alcohols; and sulfating the mixture of alcohols to form alcohol sulfates.

An embodiment provides an expression cassette. The expression cassette may comprise one or more polynucleotide encoding an intein-modified protease having an enhanced solubility. The encoded intein-modified protease may be any one of the intein-modified proteases described herein. The expression cassette may comprise a polynucleotide encoding a first precursor. The expression cassette may comprise a polynucleotide encoding the second precursor. The expression cassette may comprise a polynucleotide encoding a first precursor and a second precursor. The one or more polynucleotides may comprise, consist essentially of, or consist of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to a reference sequence of SEQ ID NO: 3, which is a sequence encoding the first precursor NI-DPNG-Trx shown in FIG. 1. The one or more polynucleotides may comprise, consist essentially of, or consist of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID: 4, which is a sequence encoding the second precursor Trx-DPNG-MTT-IC shown in FIG. 1.

The one or more polynucleotides may include a sequence encoding any one of the target proteases described herein. The one or more polynucleotides may together encode the parts of Subtilisin Carlsberg, Subtilisin BPN, SAPB from Bacillus pumilus (CBS), BPP— A protease from B. pumilus MS-1, or AprB from Bacillus sp. B001 protease. The one or more polynucleotides may encode a protease from Bacillus licheniformis (UniProt accession number is: Q6PNN5. The one or more polynucleotides may comprise, consist essentially of, or consist of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 7, which is a sequence encoding a Savinase.

The expression cassette may comprise one or more polynucleotides encoding any one of the inteins described herein. The one or more polynucleotides may encode the N-intein and C-intein parts of gp41-1, Cbu_DnaB, Mja_GF-6P, Mja_Hyp-1, Mja_IF2, Mja_Pol-1, Pab_CDC21-1, Pab_IF2-N, Pab_VMA, Pho_IF2, Pho_VMA, Rma_DnaB, Sru_DnaB, TagPol-1_Tsp-TY_Pol-1, Ter_RIR1-4, Tko_IF2, or Tth-HB27_DnaE-2 intein. Two polynucleotides of the one or more polynucleotides may comprise, consist essentially of, or consist of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 10, which a sequence encoding the gp41-1 intein. The one or more polynucleotide may encode N-intein of the intein, C-intein of the intein or both. The one or more polynucleotide may comprise, consist essentially of, or consist of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 12, which is a sequence encoding the gp41-1 N-intein. The one or more polynucleotide may comprise, consist essentially of, or consist of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 13, which is a sequence encoding the gp41-1 C-intein.

The one or more polynucleotides may further encode a first solubility enhancer, a second solubility enhancer or both. The one or more polynucleotides may encode a Trx domain. A sequence of the one or more polynucleotides may comprise, consist essentially of, or consist of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 52, which is a sequence encoding the Trx domain included in NI shown in FIG. 1. A sequence of the one or more polynucleotides may comprise, consist essentially of, or consist of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 54, which is a sequence encoding the Trx domain included in IC shown in FIG. 1.

An embodiment comprises a polynucleotide comprising, consisting essentially of, or consisting of a sequence that has at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity along its length to a contiguous portion of a polynucleotide having any one of the sequences set forth herein or the complements thereof. The contiguous portion may be any length up to the entire length of a sequence set forth herein or the complement thereof.

Determining percent identity of two amino acid sequences or two nucleic acid sequences may include aligning and comparing the amino acid residues or nucleotides at corresponding positions in the two sequences. If all positions in two sequences are occupied by identical amino acid residues or nucleotides then the sequences are said to be 100% identical. Percent identity is measured by the Smith Waterman algorithm (Smith T F, Waterman M S 1981 “Identification of Common Molecular Subsequences,” J Mol Biol 147: 195-197, which is incorporated herein by reference as if fully set forth).

In an embodiment, trans-splicing intein technology may be used to regulate protease activity. In this approach, a protease may be split between catalytic residues in two inactive fragments, which may be individually expressed as fusion to trans-splicing inteins. Mixing may trigger trans-intein mediated association of inactive fragments, splicing and seamless joining of the inactive parts by a peptide bond to fully functional active protease.

Construction, expression and detergent dilution inducible properties of a trans-splicing intein regulated liquid laundry protease, Savinase, have been described in PCT/US2013/063304, which is incorporated by reference herein as if fully set forth. Methods that improve formulation stability and detergent dilution inducible protease activity to levels relevant in commercial liquid laundry application are described herein.

An embodiment provides a method of regulating protease activity. The method includes combining any one or more of the intein-modified proteases disclosed herein with components of a home care product and may include one or more effectors to form a mixture. As used herein, home care products refers to any product used for cleaning or treating the home or its content. The home care products herein include personal care products for cleaning or conditioning of the person. The intein-modified protease in the mixture may be inactive in terms of at least protease activity or splicing activity. The one or more effectors may be capable of suppressing splicing of the intein-modified protease in the mixture. The suppression may be reversible. The step of causing splicing may include one of diluting, reducing, or removing the one or more effectors. After splicing, protease activity of the target protease may be restored. The one or more effectors may be but are not limited to sodium salt supplements, potassium salt supplements, ammonium salt supplements, charged polymeric salt supplements, or polyol supplements. The one or more effectors may be selected from the group consisting of: sodium chloride, tetrasodium iminodisuccinate, disodium succinate, disodium tartrate, potassium lactate, potassium citrate, potassium chloride, sodium nicotinate, ammonium sulfate, ammonium nitrate, lithium citrate, sodium polyaspartate, sodium polyacrylate, tetraethylene glycol, polyethylene glycol, tetraglycol, propylene carbonate, mono propylene glycol, glycerol, and tomadol. The one or more effectors may include potassium chloride. The potassium chloride concentration may be in a range from 0.1 M to 5.0 M. The concentration may be 0.1 M, 0.2 M, 0.3 M, 0.4 M, 0.5 M, 0.6 M, 0.7 M, 0.8 M, 0.9 M, 1.0 M, 1.1 M, 1.2 M, 1.3M, 1.4M, 1.5 M, 1.6 M, 1.7 M, 1.8 M, 1.9 M, 2.0 M, 2.1 M, 2.2 M, 2.3 M, 2.4 M, 2.5 M, 2.6 M, 2.7 M, 2.8 M, 2.9 M, 3.0 M, 3.1 M, 3.2 M, 3.3 M, 3.4 M, 3.5 M, 3.6 M, 3.7 M, 3.8 M, 3.9 M, 4.0 M, 4.1 M, 4.2 M, 4.3 M, 4.4 M, 4.5 M, 4.6 M, 4.7 M, 4.8 M, 4.9, 5.0 M, or any value between any two of the foregoing concentration points. The potassium chloride concentration may be in a range from 0.5 M to 2.0 M. The concentration may be 0.5 M, 0.6 M, 0.7 M, 0.8 M, 0.9 M, 1.0 M, 1.1 M, 1.2 M, 1.3M, 1.4M, 1.5 M, 1.6 M, 1.7 M, 1.8 M, 1.9 M, 2.0 M0.5 M, 0.6 M, 0.7 M, 0.8 M, 0.9 M, 1.0 M, 1.1 M, 1.2 M, 1.3M, 1.4M, 1.5 M, 1.6 M, 1.7 M, 1.8 M, 1.9 M, 2.0 M, or any value between any two of the foregoing concentration points. The concentrations of any one of the effectors listed herein may be similar to the concentrations of the potassium chloride.

In an embodiment, the step of causing may include diluting the mixture with a liquid. The amount of the liquid added to the mixture in the diluting step may be an amount satisfying a ratio of the mixture to liquid selected from the value of less than or equal to one of 1:5 (v:v), 1:10 (v:v), 1:20 (v:v), 1:50 (v:v): 1:60 (v:v), 1:70 (v:v), 1:80 (v:v), 1:90 (v:v), 1:100 (v:v), 1:150 (v-v), 1:200 (v:v), 1:250 (v:v), 1:300 (v:v), 1:350 (v:v), or 1:400 (v:v), or any ratio in a range between any two of the foregoing (endpoints inclusive). For example, the mixture to liquid ratio may be a value less than any integer or non-integer number selected from 1:5 to 1:10. The mixture-to-liquid ratio may be equal to 1:5 (v:v), 1:10 (v:v), 1:20 (v:v), 1:50 (v:v): 1:60 (v:v), 1:70 (v:v), 1:80 (v-v), 1:90 (v:v), 1:100 (v:v), 1:150 (v:v), 1:200 (v:v), 1:250 (v:v), 1:300 (v:v), 1:350 (v:v), or 1:400 (v:v) or any ratio in a range between any two of the foregoing (endpoints inclusive). For example, the liquid to mixture ratio may be a value equal to any integer or non-integer number in the range from 1:5 to 1:10. The liquid may be water. The liquid may be an aqueous buffer. The components of the home care product may be but is not limited to detergent, soap, industrial cleaner, or dish washing liquid. The dilution may cause splicing of the intein-modified protease and restoring activity of the target protease.

An embodiment provides a method of screening for effectors of dilution inducible intein-modified protease activity in liquid laundry detergent. The method may comprise mixing liquid laundry detergent with any one of the first precursor and the second precursor described herein to obtain a mixture. The method may comprise adding one or more compounds to the mixture. The method may comprise diluting the mixture with a liquid. The method may also comprise identifying compounds that suppress splicing of the N-intein and C-intein included in the respective first and second precursors and restoring the activity of the target protease. An embodiment also provides adding one or more effectors to a liquid laundry detergent formulated mixtures to reversibly inhibit an intein-modified protease.

An embodiment provides a home care product. The home care product may include any one of the intein-modified proteases disclosed herein and one or more effectors. The home care product may comprise a dishwashing detergent, a laundry detergent, an industrial cleaner, or a soapless soap. As used herein, the term “detergent” refers to a surfactant or a mixture of surfactants. The term “soapless soap” refers to a soap free liquid cleanser with a slightly acidic pH. The home care product may comprise any other type of a cleaning agent.

The home care product may comprise detergent as powder. The home care product may comprise detergent provided in liquid formulation. The liquid detergent formulation may contain water softeners, surfactants, bleach, enzymes, brighteners, fragrances, and many other agents. The liquid detergent formulation may include a combination of anionic and nonionic surfactants, builders to remove the hardness ions, a variety of antiredeposition agents, dye transfer inhibitors that prevent dye from coming off one fabric and getting deposited on another, soil release polymers to provide a barrier to the fabric, optical brighteners, enzyme stabilizers, viscosity control compounds, pH control compounds, soap and silicones to control excessive foaming, preservatives for microbial control, perfume and dye for scent and appearance, bleaching agents, water, solubilizers or other additives to improve performance characteristics. The liquid detergent formulation may comprise anionic surfactants that are alkylbenzenesulphonates, or other anionic surfactants. The liquid detergent formulation may comprise nonionic surfactants that are ethoxylated fatty alcohols. The liquid detergent formulation may comprise builder to remove the hardness ions selected from sodium citrate, tetrasodium EDTA or an acrylic polymer. The liquid detergent formulation may comprise a dye transfer inhibitor selected from PVP K-30, Chromabond S-100, or Chromabond S-400. The liquid detergent formulation may comprise a soil release polymer selected from Sorez 100 a polyethylene glycol polyester copolymer, or Repel-O-Tex SRP-6, a polyethylene glycol polyester. The liquid detergent formulation may comprise the optical brightener that is Tinopal CBS-X, or any other optical brightener. The liquid detergent formulation may comprise the enzyme stabilizer selected from calcium chloride, sodium tetraborate, propylene glycol, sodium formate, sodium citrate or monoethanolamine. The liquid detergent formulation may comprise the viscosity control compound of propylene glycol, sodium xylene sulfonate, or polymers. The liquid detergent formulation may comprise the pH control compound of citric acid or monoethanolamine.

The home care product herein may include one or more effectors. The one or more effectors may be but are not limited to sodium chloride, tetrasodium iminodisuccinate, disodium succinate, disodium tartrate, potassium lactate, potassium citrate, potassium chloride, sodium nicotinate, ammonium sulfate, ammonium nitrate, lithium citrate, sodium polyaspartate, sodium polyacrylate, tetraethylene glycol, polyethylene glycol, tetraglycol, propylene carbonate, mono propylene glycol, glycerol, or tomadol.

An embodiment provides a method of storing a protease in a mixture. The method may include making any one intein-modified proteases described herein. The method may include combining the intein-modified protease with a home care product and one or more effectors to form a mixture. The home care product may be selected from the group consisting of: detergent, soap, industrial cleaner, and dish washing liquid. The one or more effectors may be selected be any one of effectors disclosed herein. The mixture may be stored for any length of time. The mixture may be stored, for a period of time from one hour to a year. The mixture may be stored for one week, two weeks, three weeks, four weeks, five weeks, six weeks, seven weeks, or eight weeks.

The home care product may include iProtease, which refers to any one of the intein-modified proteases described herein. The home care product may comprise iSavinase. iSavinase storage stability in liquid laundry detergents may be comparable with the inhibitor stabilized Savinase under accelerated ageing conditions over eight weeks. iSavinase stain removal activity on blood, milk or ink stained fabric (EMPA117) may be comparable with the intein unmodified Savinase at equimolar loading of the enzymes.

The following list includes particular embodiments of the present invention. But the list is not limiting and does not exclude alternate embodiments, or embodiments otherwise described herein. Percent identity described in the following embodiments list refers to the identity of the recited sequence along the entire length of the reference sequence.

EMBODIMENTS

1. An intein-modified protease comprising: a first precursor and a second precursor: the first precursor comprises an N-extein of a target protease fused to a solubility enhanced N-intein of a trans-splicing intein, and the carboxy terminus of the N-extein is fused to the amino terminus of the solubility enhanced N-intein; the second precursor comprises a solubility enhanced C-intein of the trans-splicing intein fused to a C-extein of the target protease, and the carboxy terminus of the solubility enhanced C-intein is fused to the amino terminus of the C-extein; and the first precursor is separated from the second precursor prior to trans-splicing; wherein the intein-modified protease has enhanced solubility and reduced or inhibited activity compared to the target protease and the activity of the target protease is obtained upon trans-splicing of the intein-modified protease and fusion of the N-extein and the C-extein. 2. The intein-modified protease of embodiment 1, wherein the solubility enhanced N-intein comprises an N-intein and a first solubility enhancer and the carboxy terminus of the N-intein is fused to the first solubility enhancer by a first linker. 3. The intein-modified protease of one or both of embodiments 1-2, wherein the solubility enhanced C-intein includes a C-intein and a second solubility enhancer, and the second solubility enhancer is fused to the amino terminus of the C-intein by a second linker. 4. The intein-modified protease of one or more of embodiments 2-3, wherein at least one of the first solubility enhancer or the second solubility enhancer is independently selected from the group consisting of: a thioredoxin domain Trx, small ubiquitin-related protein SUMO, glutathione-S transferase GST, maltose-binding protein MBP, N utilization substance A NusA, and seventeen kilodalton protein Skp. 5. The intein-modified protease of one or more of embodiments 2-4, wherein each of the first solubility enhance and the second solubility enhancer comprises a thioredoxin domain Trx. 6. The intein-modified protease of one or more embodiments 2-5, wherein the first solubility enhancer comprises, consists essentially of, or consists of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to a sequence of SEQ ID NO: 51, and the second solubility enhancer comprises, consists essentially of, or consists of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to a sequence of SEQ ID NO: 53. 7. The intein-modified protease of one or more of embodiments 2-6, wherein at least one of the first linker or the second linker is a DPNG linker. 8. The intein-modified protease of one or more of preceding embodiments, wherein the target protease is an enzyme selected from the group consisting of: EC3.4.99 proteases, EC3.4.21.62 proteases, keratinases, serine proteases, alkaline proteases, acid protease, metallo proteases, cysteine proteases, aspartate proteases, ATP-dependent proteases, and Subtilisin family proteases. 9. The intein-modified protease of one or more of preceding embodiments, wherein the target protease comprises a target protease selected from the group consisting of a Savinase, an alkaline protease Q6PNN5, and acid protease B8NLY9_PEPA_ASPEN. 10. The intein-modified protease of one or more of preceding embodiments, wherein the target protease comprises, consists essentially of, or consists of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to a sequence selected from the group consisting of SEQ ID NO: 6, 8 and 9. 11. The intein-modified protease of one or more of preceding embodiments, wherein the intein is selected from the group consisted of: gp41-1, Cbu_DnaB, Mja_GF-6P, Mja_Hyp-1, Mja_IF2, Mja_Pol-1, Pab_CDC21-1, Pab_IF2-N, Pab_VMA, Pho_IF2, Pho_VMA, Rma_DnaB, Sru_DnaB, TagPol-1_Tsp-TY_Pol-1, Ter_RIR1-4, Tko_IF2, and Tth-HB27_DnaE-2 intein. 12. The intein-modified protease of one or more of preceding embodiments, wherein the intein is gp41-1 intein and comprises, consists essentially of, or consists of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 11. 13. The intein-modified protease of one or more of preceding embodiments, wherein the N-intein comprises, consists essentially of, or consists of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity a sequence selected from the group consisting of SEQ ID NOS: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, and 46 and the C-intein comprises, consists essentially of, or consists of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity a sequence selected from the group consisting of SEQ ID NOS: 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, and 47, and the N-intein and the C-intein together form a trans-splicing intein or variant thereof selected from the group consisting of: gp41-1, Cbu_DnaB, Mja_GF-6P, Mja_Hyp-1, Mja_IF2, Mja_Pol-1, Pab_CDC21-1, Pab_IF2-N, Pab_VMA, Pho_IF2, Pho_VMA, Rma_DnaB, Sru_DnaB, TagPol-1_Tsp-TY_Pol-1, Ter_RIR1-4, Tko_IF2, and Tth-HB27_DnaE-2. 14. The intein-modified protease of one or more of preceding embodiments, wherein the first precursor comprises, consists essentially of, or consists of an amino acid sequence having 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to a reference sequence of SEQ ID NO: 1. 15. The intein-modified protease of one or more of preceding embodiments, wherein the second precursor comprises, consists essentially of, or consists of an amino acid sequence having 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to a reference sequence of SEQ ID NO: 2. 16. An expression cassette comprising one or more polynucleotides encoding a first precursor or a second precursor of an intein-modified protease,

wherein the first precursor comprises an N-extein of a target protease fused to a solubility enhanced N-intein of a trans-splicing intein, and the carboxy terminus of the N-extein is fused to the amino terminus of the solubility enhanced N-intein; the second precursor comprises a solubility enhanced C-intein of the trans-splicing intein fused to a C-extein of the target protease, and the carboxy terminus of the solubility enhanced C-intein is fused to the amino terminus of the C-extein; and the first precursor is separated from the second precursor prior to trans-splicing; and

wherein upon expression from the expression cassette the intein-modified protease would have enhanced solubility and reduced or inhibited activity compared to the target protease, and the activity of the target protease would restored restored upon trans-splicing of the intein-modified protease and fusion of the N-extein and the C-extein.

17. The expression cassette of embodiment 16, wherein the one or more polynucleotides encode the solubility enhanced N-intein comprising the N-intein and a first solubility enhancer, and the carboxy terminus of the N-intein is fused to the first solubility enhancer by a first linker. 18. The expression cassette of one or more of embodiments 16-17, wherein the one or more polynucleotides encode the solubility enhanced C-intein comprising a C-intein of an intein and the second solubility enhancer, and the second solubility enhancer is fused to the amino terminus of the C-intein by a second linker. 19. The expression cassette of one or more of embodiments 16-18, wherein the one or more polynucleotides encode the first solubility enhancer or the second solubility enhancer selected from the group consisting of: a thioredoxin domain Trx, small ubiquitin-related protein SUMO, glutathione-S transferase GST, maltose-binding protein MBP, N utilization substance A NusA, and seventeen kilodalton protein Skp. 20. The expression cassette of one or more of embodiments 17-19, wherein the one or more polynucleotides encode each of the first solubility enhancer and the second solubility enhancer comprising the thioredoxin domain Trx. 21. The expression cassette of one or more of embodiments 17-20, wherein the one or more polynucleotides comprise, consist essentially of, or consists of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 52. 22. The expression cassette of one or more of embodiments 17-21, wherein the one or more the polynucleotide comprise, consist essentially of, or consists of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 54. 23. The expression cassette of one or more of embodiments 17-22, wherein the one or more polynucleotides encode a DPNG linker. 24. The expression cassette of one or more of embodiments 16-23, wherein the the one or more polynucleotides encode the target protease selected from the group consisting of: EC3.4.99 proteases, EC3.4.21.62 proteases, keratinases, serine proteases, alkaline proteases, metallo proteases, cysteine proteases, aspartate proteases, ATP-dependent proteases, and Subtilisin family proteases. 25. The expression cassette one or more of embodiments 16-24, wherein the one or more polynucleotides encode a target protease selected from the group consisting of: a Savinase, an alkaline protease Q6PNN5, and acid protease B8NLY9_PEPA_ASPEN. 26. The expression cassette of one or more of embodiments 16-25, wherein the one or more polynucleotides encode a savinase and comprising, consisting essentially of, or consisting of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 7. 27. The expression cassette of one or embodiments 16-26, wherein the one or more polynucleotides encode an intein selected from the group consisted of: gp41-1, Cbu_DnaB, Mja_GF-6P, Mja_Hyp-1, Mja_IF2, Mja_Pol-1, Pab_CDC21-1, Pab_IF2-N, Pab_VMA, Pho_IF2, Pho_VMA, Rma_DnaB, Sru_DnaB, TagPol-1_Tsp-TY_Pol-1, Ter_RIR1-4, Tko_IF2, or Tth-HB27_DnaE-2 intein. 28. The expression cassette of embodiment 27, wherein the one or more polynucleotides encode a gp41-1 intein and comprise, consist essentially of, or consists of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 10. 29. The expression cassette of embodiment 28, wherein the one or more polynucleotides encode an N-intein of the gp41-1 intein and comprise, consist essentially of, or consists of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 12. 30. The expression cassette of claim 28, wherein the one or more polynucleotides encode a C-intein of the gp41-1 intein and comprise, consist essentially of, or consists of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 13. 31. The expression cassette of any one or more embodiments 16-30, wherein the one or more polynucleotides encode the first precursor and comprise, consist essentially of, or consists of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID: 3. 32. The expression cassette of any one or more embodiments 16-31, wherein the one or more polynucleotides encode the second precursor and comprise, consist essentially of, or consists of a sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 4. 33. A composition comprising: a first precursor of an intein-modified protease and a second precursor of an intein-modified protease, the first precursor comprises an N-extein of a target protease fused to a solubility enhanced N-intein of a trans-splicing intein, and the carboxy terminus of the N-extein is fused to the amino terminus of the solubility enhanced N-intein; the second precursor comprises a solubility enhanced C-intein of the trans-splicing intein fused to a C-extein of the target protease, and the carboxy terminus of the solubility enhanced C-intein is fused to the amino terminus of the C-extein; and the first precursor is separated from the second precursor prior to trans-splicing; wherein the intein-modified protease has enhanced solubility and reduced activity compared to the target protease and the activity of the target protease is obtained upon trans-splicing of the intein-modified protease and fusion of the N-extein and the C-extein. 34. The composition of embodiment 33, wherein the solubility enhanced N-intein comprises an N-intein and a first solubility enhancer, and the carboxy terminus of the N-intein is fused to the first solubility enhancer by a first linker; and/or the solubility enhanced C-intein comprises a C-intein and a second solubility enhancer, and the second solubility enhancer is fused to the amino terminus of the C-intein by a second linker. 35. The composition of one or both of embodiments 33-34, wherein the first solubility enhancer or the second solubility enhancer is selected from the group consisting of: a thioredoxin domain Trx, small ubiquitin-related protein SUMO, glutathione-S transferase GST, maltose-binding protein MBP, N utilization substance A NusA, and seventeen kilodalton protein Skp. 36. The composition of one or more of embodiments 33-35, wherein each of the first solubility enhancer and the second solubility enhancer comprises the thioredoxin domain Trx. 37. The composition of one or more of embodiments 34-36, wherein the first solubility enhancer comprises, consists essentially of, or consists of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 51; and/or the second solubility enhancer comprises, consists essentially of, or consists of an amino acid sequence with at least 90% identity to SEQ ID NO: 53. 38. The composition of one or more of embodiments 34-37, wherein the first linker or the second linker is a DPNG linker. 39. The composition of one or more of embodiments 33-38, wherein the target protease is an enzyme selected from the group consisting of: EC3.4.99 proteases, EC3.4.21.62 proteases, keratinases, serine proteases, alkaline proteases, acid proteases, metallo proteases, cysteine proteases, aspartate proteases, ATP-dependent proteases, Subtilisin family proteases, Savinase, alkaline protease Q6PNN5, and acid protease B8NLY9_PEPA_ASPEN. 40. The composition of one or more of embodiments 33-39, wherein the target protease comprises, consists essentially of, or consists of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to a sequence selected from the group consisting of SEQ ID NOS: 6, 8, and 9. 41. The composition of one or more of embodiments 3-40, wherein the N-intein comprises, consists essentially of, or consists of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity a sequence selected from the group consisting of SEQ ID NOS: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, and 46, the C-intein comprises, consists essentially of, or consists of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity a sequence selected from the group consisting of SEQ ID NOS: 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, and 47, and the N-intein and the C-intein together form a trans-splicing intein or a variant thereof selected from the group consisting of: gp41-1, Cbu_DnaB, Mja_GF-6P, Mja_Hyp-1, Mja_IF2, Mja_Pol-1, Pab_CDC21-1, Pab_IF2-N, Pab_VMA, Pho_IF2, Pho_VMA, Rma_DnaB, Sru_DnaB, TagPol-1_Tsp-TY_Pol-1, Ter_RIR1-4, Tko_IF2, and Tth-HB27_DnaE-2. 42. The composition of one or more of embodiments 33-41, wherein the first precursor comprises, consists essentially of, or consists of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 1; and/or the second precursor comprises, consists essentially of, or consists of an amino acid sequence with at least 70, 72, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100% identity to SEQ ID NO: 2. 43. A home care product comprising an intein-modified protease of one or more of embodiments 1-15 or the compositions of one or more of embodiments 33-42, and one or more effectors. 44. The home care product of embodiment 43, wherein the one or more effectors is capable of suppressing trans-splicing. 45. The home care product of embodiment 44, wherein the suppressing is reversible. 46. The home care product of one or more of embodiments 43-45, further comprising at least one agent selected from the group consisting of: a detergent, a soap, industrial cleaner, a soapless soap and dish washing liquid. 47. The home care product of one or more of embodiments 43-46, wherein the one or more effectors are selected from the group consisting of: sodium chloride, tetrasodium iminodisuccinate, disodium succinate, disodium tartrate, potassium lactate, potassium citrate, potassium chloride, sodium nicotinate, ammonium sulfate, ammonium nitrate, lithium citrate, sodium polyaspartate, sodium polyacrylate, tetraethylene glycol, polyethylene glycol, tetraglycol, propylene carbonate, mono propylene glycol, glycerol, and tomadol. 48. The home care product of one or more of embodiments 43-47 further comprising at least one ingredient selected from the group consisting of: water softeners, surfactants, bleach, enzymes, brighteners, fragrances, anionic surfactants, nonionic surfactants, builders to remove the hardness ions, antiredeposition agents, dye transfer inhibitors, soil release polymers, optical brighteners, enzyme stabilizers, viscosity control compounds, pH control compounds, soap and silicones to control excessive foaming, preservatives for microbial control, perfume and dye for scent and appearance, bleaching agents, water, solubilizers, alkylbenzenesulphonates, ethoxylated fatty alcohols, sodium citrate, tetrasodium EDTA or an acrylic polymer, PVP K-30, Chromabond S-100, Chromabond S-400, Sorez 100, Repel-O-Tex SRP-6, Tinopal CBS-X, calcium chloride, sodium tetraborate, propylene glycol, sodium formate, sodium citrate, monoethanolamine, propylene glycol, sodium xylene sulfonate, polymers, and citric acid. 49. The home care product of one or more of embodiments 43-48 further comprising a fuel additive selected from the group consisting of: a long-chain amine or amide, polyisobuteneamine, polyisobuteneamide and succinimide. 50. The home care product of one or more of embodiments 43-49 further comprising a biological reagent. 51. The home care product of any one or more of embodiments 43-50, wherein the one or more effectors are selected from the group consisting of: sodium chloride, tetrasodium iminodisuccinate, disodium succinate, disodium tartrate, potassium lactate, potassium citrate, potassium chloride, sodium nicotinate, ammonium sulfate, ammonium nitrate, lithium citrate, sodium polyaspartate, sodium polyacrylate, tetraethylene glycol, polyethylene glycol, tetraglycol, propylene carbonate, mono propylene glycol, glycerol, and tomadol. 52. A method of regulating protease activity comprising:

forming the home care product of any one or more of embodiments 43-51.

53. The method of embodiment 36, wherein forming comprises combining the composition of any one or more of embodiments 33-42 with one or more effectors. 54. The method of one or both of embodiments 52-53 comprising causing splicing of the intein-modified protease. 55. The method of one or more of embodiments 52-54, wherein the one or more effectors are selected from the group consisting of: sodium salt supplements, potassium salt supplements, ammonium salt supplements, charged polymeric salt supplements, and polyol supplements. 56. The methods of one or more of embodiments 52-55, wherein the one or more effectors are selected from the group consisting of: sodium chloride, tetrasodium iminodisuccinate, disodium succinate, disodium tartrate, potassium lactate, potassium citrate, potassium chloride, sodium nicotinate, ammonium sulfate, ammonium nitrate, lithium citrate, sodium polyaspartate, sodium polyacrylate, tetraethylene glycol, polyethylene glycol, tetraglycol, propylene carbonate, mono propylene glycol, glycerol, and tomadol. 57. The method of one or more of embodiments 52-56, wherein the one or more effectors comprises potassium chloride. 58. The method of embodiment 57, wherein the potassium chloride concentration is in a range from 0.1 M to 5.0 M. 59. The method of method of one or both of embodiments 57 or 58 wherein the potassium chloride concentration is in a range from 0.5 M to 2.0 M. 60. The method of one or more embodiments 54-59, wherein the step of causing splicing includes diluting the mixture with a liquid to a mixture:liquid ratio of less or equal to one selected from the group consisting of: 1:5, 1:10, 1:20, 1:50: 1:60, 1:70, 1:80, 1:90, 1:100, 1:150, 1:200, 1:250, 1:300, 1:350, and 1:400 of a mixture to liquid. 61. The method of embodiment 60, wherein the liquid is one of water and an aqueous buffer. 63. The method of one or more of embodiments 52-61, wherein the protease activity of the target protease is obtained upon splicing of the intein-modified protease. 64. A method of storing a protease in a mixture comprising: making an intein-modified protease of any one or more of embodiments 1-15, or the compositions of any one or more of embodiments 33-42, and combining the intein-modified protease or the composition with at least one agent selected from the group consisting of: detergent, a soap, an industrial cleaner, and a dishwashing liquid and one or more effectors to form a mixture.

Further embodiments herein may be formed by supplementing an embodiment with one or more element from any one or more other embodiment herein, and/or substituting one or more element from one embodiment with one or more element from one or more other embodiment herein.

EXAMPLES

The following non-limiting examples are provided to illustrate particular embodiments. The embodiments throughout may be supplemented with one or more detail from one or more example below, and/or one or more element from an embodiment may be substituted with one or more detail from one or more example below.

Example 1. Trans-Splicing Intein Technology for Regulating Activity of Proteases

Trans-splicing intein technology may be used regulate protease activity. In this approach the protease is split between catalytic residues to two inactive fragments, which are individually expressed as fusion to trans-splicing inteins. Mixing in an aqueous environment triggers trans-intein mediated association of inactive fragments, splicing and seamless joining of the inactive parts to fully functional active protease.

Construction, expression and detergent dilution inducible properties of a trans-splicing intein regulated liquid laundry protease, Savinase have been described in PCT patent application PCT/US2013/063304, which is incorporated herein by reference as if fully set forth. Methods that improve formulation stability and detergent dilution inducible protease activity to levels relevant in commercial liquid laundry application are described herein.

Example 2. Solubility Optimized Molecules

Detergent refers to liquid laundry detergents. Detergent-1 and-4 were enzyme-free, optical-brightener-free and coloring agent-free standard liquid detergent formulations. Detergent-1 could contain deionized water, Neodol 25_7, LAS acid, Prifac 5908, Dequest 2010, SLES 3EO, sodium sulfite, Sokalan HP20, MPG, MEA, TEA, glycerol, Tinopal 5BMGX and other common liquid laundry detergent components. Detergent-1 had a pH of ˜8.3±0.2 and conductivity of 3890 Simens. Detergent-4 had a pH ˜7.3±0.2 and conductivity of 22400 Simens.

Detergent-2 and -3 were optical brightener and coloring agent free commercial brand detergents with formulated protease. Detergent-2 had a pH of ˜8.8±0.2, and conductivity of 3900 Simens. Detergent-3 had a pH of ˜8.3±0.2, and conductivity of 7090 Simens. Protease activity was inactivated by heat treatment at 80° C. for 90 min. After cooling to room temperature, the absence of protease was verified as follows: detergent was diluted to 50% v/v with deionized water. To 25 L 50% detergent, 75 μL of BR buffer (40 mM sodium phosphate dibasic, 40 mM sodium acetate, 40 mM sodium borate were added, pH adjusted to 9.0 with NaOH), 100 μL of FAAF-pNA substrate (500 jiM) was added, and absorbance was read at 400 nm in a kinetic assay at 37° C. Assay plates were sealed and inspected after overnight incubation at 37° C. for yellow color development indicative of protease activity. Heat treated detergent had no measurable protease activity. The unheated detergent showed robust and instant protease activity under the same conditions.

Savinase is an extracellular alkaline protease from Bacillus lentus (Uniprot accession number is: P29600 (http://www.uniprot.org/uniorot/P29600) and a common protease in liquid laundry detergents. Examples herein utilize Savinase having the amino acid sequence of SEQ ID NO: 6.

Savinase Enzyme Assay

The substrate for the Savinase enzyme assay is the chromogenic peptide substrate N-Succinyl-Ala-Ala-Pro-Phe p-nitroanilide (Sigma-Aldrich). This substrate is highly specific for subtilisin-like enzymes (Davis et al., 1999) and it can support enzyme assays in bacterium suspensions (Bonifait et al., 2010, which is incorporated by reference herein as if fully set forth). In a typical assay, 100 μL of lysate, or bacterium suspension is added to 20 μl of the chromogenic substrate N-succinyl-Ala-Ala-Pro-Phe-pNa (2 mg/mL in 50% dimethyl formamide), the reaction mixture is incubated at 37° C. for variable times and the release of pNA is quantified by measuring the absorbance at 415 nm (Bonifait et al., 2010). This protocol is easily adaptable through automation to support screening by performing high throughput protease activity assays. Proteolytic activity can also be measured by digestion of AZO-casein (Vazquez et al. 2004). Twenty microliters of lysate are incubated in 384-well plate with 20 μL of 1% (w/v) AZO-casein in Tris-HCl buffer (0.1 M, pH8.0) and 0.5 mM CaCl₂) at 55° C. for 30 min. After stopping the reaction with 40 μL of 5% (w/v) trichloracetic acid, reaction mixture is centrifuged and absorbance of supernatant was measured at 340 nm.

iSavinase refers to an intein-modified protease system, where the target protease is a Savinase. More generally, any intein-modified proteases system herein, including the iSavinase system, may be referred to as iProtease. Savinase molecules may be generated by trans-splicing of the intein-modified precursors. The intein-modified precursor molecule, which is expressed prior to intein splicing, is referred to as a “NI” (representing in frame fusion of the Savinase N-terminal fragment (N-extein) including the pro-domain and sequences ending with residue 316 (numbering based on preproSavinase) to the N-terminal part of the Gp41-1 intein (I^(N)), and IC (representing the fusion of Gp41-1 C-terminal intein (I^(C)) to the C-terminal part (C-extein) of Savinase starting with serine 317. The splice product that has the amino extein (N) and carboxy extein (C) seamlessly joined called “NC”, which after auto-cleavage of the pro-domain results in the active enzyme, iProtease. “(NI+IC) premix” refers to a mix of splicing competent NI and IC in an inactive state that has no protease activity but can be induced by dilution to yield fully active iProtease.

NI and IC described herein are solubility optimized versions of the prototype molecule iProtease:S317-Gp41-1 NI and IC described in PCT/US2013/063304, which is incorporated herein by reference as if fully set forth.

The nucleotide sequence of the wild type gp41-1 split intein (length: 375 bp) with N-intein and C-intein parts fused is as follows. The C-intein part is in bold and underlined.

(SEQ ID NO: 10) TGTCTGGACCTGAAAACGCAAGTGCAAACCCCGCAAGGCATGAAGGAAA TCTCAAACATCCAAGTCGGTGACCTGGTGCTGTCGAATACCGGCTATAAC GAAGTGCTGAATGTTTTTCCGAAGAGCAAAAAGAAATCTTACAAGATCAC GCTGGAAGATGGCAAGGAAATTATTTGCAGCGAAGAACATCTGTTCCCGA CCCAGACGGGCGAAATGAATATCTCCGGCGGTCTGAAAGAAGGCATGTG TCTGTACGTCAAGGAA ATGATGCTGAAGAAAATTCTGAAGATCGAAGA ACTGGATGAACGTGAACTGATTGACATCGAAGTTAGCGGCAACCATC TGTTTTACGCGAATGACATTCTGACCCACAAC

The protein sequence of the wild type gp41-1 split intein with fused N- and C-intein parts is as follows. The C-intein part is in bold and underlined.

(SEQ ID NO: 11) CLDLKTQVQTPQGMKEISNIQVGDLVLSNTGYNEVLNVFPKSKKKSYKIT  50 LEDGKEIICSEEHLFPTQTGEMNISGGLKEGMCLYVKE MMLKKILKIEEL 100 DERELIDIEVSGNHLFYANDILTHN

The map of gp41-1 sequences is shown below:

  1 TGTCTGGACCTGAAAACGCAAGTGCAAACCCCGCAAGGCATGAAGGAAATCTCAAACATC  60  C  L  D  L  K  T  Q  V  Q  T  P  Q  G  M  K  E  I  S  N  I  61 CAAGTCGGTGACCTGGTGCTGTCGAATACCGGCTATAACGAAGTGCTGAATGTTTTTCCG 120  Q  V  G  D  L  V  L  S  N  T  G  Y  N  E  V  L  N  V  F  P 121 AAGAGCAAAAAGAAATCTTACAAGATCACGCTGGAAGATGGCAAGGAAATTATTTGCAGC 180  K  S  K  K  K  S  Y  K  I  T  L  E  D  G  K  E  I  I  C  S 181 GAAGAACATCTGTTCCCGACCCAGACGGGCGAAATGAATATCTCCGGCGGTCTGAAAGAA 240  E  E  H  L  F  P  T  Q  T  G  E  M  N  I  S  G  G  L  K  E 241 GGCATGTGTCTGTACGTCAAGGAA ATG ATGCTGAAGAAAATTCTGAAGATCGAAGAACTG 300  G  M  C  L  Y  V  K  E  M  M  L  K  K  I  L  K  I  E  E  L 301 GATGAACGTGAACTGATTGACATCGAAGTTAGCGGCAACCATCTGTTTTACGCGAATGAC 360  D  E  R  E  L  I  D  I  E  V  S  G  N  H  L  F  Y  A  N  D 361 ATTCTGACCCACAAC 375 (SEQ ID NO: 10)  I  L  T  H  N (SEQ ID NO: 11)

In the 41-1 map, the N- and C-intein parts are fused and the C-intein part is in bold and underlined.

Molecular optimization for improved solubility were all restricted to the intein parts to ensure splicing leaves no footprint in the target enzyme when the intein removes itself and seamlessly joins the flanking protein sequences to restore intact protein backbone to full activity.

FIG. 1 shows schematic drawings of the solubility optimized molecules. Referring to FIG. 1, Savinase is split between catalytic residues to Sav-N and Sav-C. Catalytic residues are: D (Asp143), H (His172), S (Ser326), relative positions are marked by vertical lines. Intein parts I^(N) and I^(C) are attached to Savinase parts Sav-N and Sav-C, respectively. Solubility engineering is restricted to the intein parts. Solubility enhancer Trx domains are attached to each intein part via a DPNG (Asp-Pro-Asn-Gly (SEQ ID NO:5)) linker. The C-intein part (I^(C)) has multiple mutations for enhanced solubility. These are M89Δ, L91T, L95T, L122G (numbering is by the position in the fused I^(N)+I^(C)).

Solubility optimized NI, termed NI-DPNG-Trx, has a C-terminal solubility enhancer thioredoxin domain (Trx, from pET32) fused via an Asp-Pro-Asn-Gly (DPNG) linker to the C-terminal end of the Gp41-1 N-intein (I^(N)) in the iProtease:S317-Gp41-1N. In the solubility optimized I^(C), termed Trx-DPNG-MTT I^(C)[G122L], the thioredoxin domain (Trx) domain is fused via an Asp-Pro-Asn-Gly (DPNG) linker N-terminal to the mutated C-intein (I^(C)) of the iProtease:S317-Gp41-1C. The mutated C-intein, MTT-IC[L122G] has four solubility enhancer mutations at positions M89Δ, L91T, L95T and L122G (numbering is by the position in the fused I^(N)+I^(C) of GP41-1).]

Nucleic acid sequences of solubility optimized iProtease NI (NI-DPNG-Trx)

(SEQ ID NO: 3)    1 ATGGCTGAAG AAGCAAAAGA AAAATATTTA ATTGGCTTTA ATGAGCAGGA AGCTGTCAGT   61 GAGTTTGTAG AACAAGTAGA GGCAAATGAC GAGGTCGCCA TTCTCTCTGA GGAAGAGGAA  121 GTCGAAATTG AATTGCTTCA TGAATTTGAA ACGATTCCTG TTTTATCCGT TGAGTTAAGC  181 CCAGAAGATG TGGACGCGCT TGAACTCGAT CCAGCGATTT CTTATATTGA AGAGGATGCA  241 GAAGTAACGA CAATGGCGCA ATCGGTACC t  TGGGGAATTA GCCGTGTGCA AGCCCCAGCT  301 GCCCATAACC GTGGATTGAC AGGTTCTGGT GTAAAAGTTG CTGTCCTCGA TACAGGGATA  361 TCCACTCATC CAGATCTAAA TATTCGTGGT GGCGCAAGCT TTGTACCAGG GGAACCGTCG  421 ACTCAAGATG GGAATGGGCA TGGCACGCAT GTGGCCGGGA CGATCGCTGC TTTAAACAAT  481 TCGATTGGCG TTCTTGGCGT AGCGCCGAGC GCTGAGCTAT ACGCTGTTAA AGTCCTAGGG  541 GCGAGCGGTT CAGGTTCGGT CAGCTCGATT GCCCAAGGAT TGGAATGGGC AGGGAACAAT  601 GGCATGCACG TTGCTAATTT GAGTTTAGGA AGCCCTTCGC CAAGTGCCAC ACTTGAGCAA  661 GCTGTTAATA GCGCGACTTC TAGAGGCGTT CTTGTTGTAG CGGCATCTGG GAACTCAGGT  721 GCAGGCTCAA TCAGCTATCC GGCGCGCTAT GCGAACGCAA TGGCAGTCGG AGCTACTGAT  781 CAAAACAACA ACCGCGCTAG CTTTTCACAG TATGGCGCAG GCCTTGACAT TGTCGCACCC  841 GGGGTAAACG TGCAGAGCAC ATACCCAGGT TGTCTGGACC TGAAAACGCA AGTGCAAACC  901 CCGCAAGGCA TGAAGGAAAT CTCAAACATC CAAGTCGGTG ACCTGGTGCT GTCGAATACC  961 GGCTATAACG AAGTGCTGAA TGTTTTTCCG AAGAGCAAAA AGAAATCTTA CAAGATCACG 1021 CTGGAAGATG GCAAGGAAAT TATTTGCAGC GAAGAACATC TGTTCCCGAC CCAGACGGGC 1081 GAAATGAATA TCTCCGGCGG TCTGAAAGAA GGCATGTGTC TGTACGTCAA GGAAgatcct 1141 aatggtATGA GCGATAAAAT TATTCACCTG ACTGACGACA GTTTTGACAC GGATGTACTC 1201 AAAGCGGACG GGGCGATCCT CGTCGATTTC TGGGCAGAGT GGTGCGGTCC GTGCAAAATG 1261 ATCGCCCCGA TTCTGGATGA AATCGCTGAC GAATATCAGG GCAAACTGAC CGTTGCAAAA 1321 CTGAACATCG ATCAAAACCC TGGCACTGCG CCGAAATATG GCATCCGTGG TATCCCGACT 1381 CTGCTGCTGT TCAAAAACGG TGAAGTGGCG GCAACCAAAG TGGGTGCACT GTCTAAAGGT 1441 CAGTTGAAAG AGTTCCTCGA CGCTAACCTG GCCTAG 

Amino acid sequences of the solubility optimized iProtease NI (NI-DPNG-Trx)

(SEQ ID NO: 1)

AEEAKEKYL IGFNEQEAVS EFVEQVEAND EVAILSEEEE VEIELLHEFE TIPVLSVELS   1 PEDVDALELD PAISYIEEDA EVIT

AQSVP WGISRVQAPA AHNRGLTGSG VKVAVLDTGI 121 STHPDLNIRG GASFVPGEPS TQDGNGHGTH VAGTIAALNN SIGVLGVAPS AELYAVKVLG 181 ASGSGSVSSI AQGLEWAGNN G

HVANLSLG SPSPSATLEQ AVNSATSRGV LVVAASGNSG 241 AGSISYPARY ANA

AVGATD QNNNRASFSQ YGAGLDIVAP GVNVQSTYPG CLDLKTQVQT 301 PQG

KEISNI QVGDLVLSNT GYNEVLNVFP KSKKKSYKIT LEDGKEIICS EEHLFPTQTG 361 E

NISGGLKE G

CLYVKEDP NG

SDKIIHL TDDSFDTDVL KADGAILVDF WAEWCGPCK

421 IAPILDEIAD EYQGKLTVAK LNIDQNPGTA PKYGIRGIPT LLLFKNGEVA ATKVGALSKG 481 QLKEFLDANL A *  

Nucleic acid sequences of the solubility optimized iProtease IC (Trx-DPNG-MTT-IC)

(SEQ ID NO: 4)   1 ATGAGCGATA AAATTATTCA CCTGACTGAC GACAGTTTTG ACACGGATGT ACTCAAAGCG  61 GACGGGGCGA TCCTCGTCGA TTTCTGGGCA GAGTGGTGCG GTCCGTGCAA AATGATCGCC 121 CCGATTCTGG ATGAAATCGC TGACGAATAT CAGGGCAAAC TGACCGTTGC AAAACTGAAC 181 ATCGATCAAA ACCCTGGCAC TGCGCCGAAA TATGGCATCC GTGGTATCCC GACTCTGCTG 241 CTGTTCAAAA ACGGTGAAGT GGCGGCAACC AAAGTGGGTG CACTGTCTAA AGGTCAGTTG 301 AAAGAGTTCC TCGACGCTAA CCTGGCCgat cctaatggtA TG ac GAAGAA AATT ac GAAG 361 ATCGAAGAAC TGGATGAACG TGAACTGATT GACATCGAAG TTAGCGGCAA CCATCTGTTT 421 TACGCGAATG ACATT gg GAC CCACAACTCA AC t TATGCCA GCTTAAACGG TACATCGATG 481 GCTACTCCTC ATGTTGCAGG TGCGGCCGCC CTTGTTAAAC AAAAGAACCC ATCTTGGTCT 541 AATGTACAAA TTCGAAATCA TCTAAAGAAT ACGGCAACTA GTTTAGGAAG CACGAACTTG 601 TATGGAAGCG GACTTGTTAA CGCAGAAGCG GCAACGCGTT AA

Amino acid sequences of the solubility optimized iProtease IC (Trx-DPNG-MTT-IC)

(SEQ ID NO: 2)   1

SDKIIHLTD DSFDTDVLKA DGAILVDFWA EWCGPCK

IA PILDEIADEY QGKLTVAKLN  61 IDQNPGTAPK YGIRGIPTLL LFKNGEVAAT KVGALSKGQL KEFLDANLAD PNG

TKKITK 121 IEELDERELI DIEVSGNHLF YANDIGTHNS TYASLNGTS

 ATPHVAGAAA LVKQKNPSWS 181 NVQIRNHLKN TATSLGSTNL YGSGLVNAEA ATR 

Map of iProtease NI is as follows:

1 M  A  E  E  A  K  E  K  Y  L  I  G  F  N  E  Q  E  A  V  S 1 ATGGCTGAAGAAGCAAAAGAAAAATATTTAATTGGCTTTAATGAGCAGGAAGCTGTCAGT 21 E  F  V  E  Q  V  E  A  N  D  E  V  A  I  L  S  E  E  E  E 61 GAGTTTGTAGAACAAGTAGAGGCAAATGACGAGGTCGCCATTCTCTCTGAGGAAGAGGAA 41 V  E  I  E  L  L  H  E  F  E  T  I  P  V  L  S  V  E  L  S 121 GTCGAAATTGAATTGCTTCATGAATTTGAAACGATTCCTGTTTTATCCGTTGAGTTAAGC 61 P  E  D  V  D  A  L  E  L  D  P  A  I  S  Y  I  E  E  D  A 181 CCAGAAGATGTGGACGCGCTTGAACTCGATCCAGCGATTTCTTATATTGAAGAGGATGCA 81 E  V  T  T  M  A  Q  S  V  P  W  G  I  S  R  V  Q  A  P  A 241 GAAGTAACGACAATGGCGCAATCGGTACCtTGGGGAATTAGCCGTGTGCAAGCCCCAGCT 101 A  H  N  R  G  L  T  G  S  G  V  K  V  A  V  L  D  T  G  I 301 GCCCATAACCGTGGATTGACAGGTTCTGGTGTAAAAGTTGCTGTCCTCGATACAGGGATA 121 S  T  H  P  D  L  N  I  R  G  G  A  S  F  V  P  G  E  P  S 361 TCCACTCATCCAGATCTAAATATTCGTGGTGGCGCAAGCTTTGTACCAGGGGAACCGTCG 141 T  Q  D  G  N  G  H  G  T  H  V  A  G  T  I  A  A  L  N  N 421 ACTCAAGATGGGAATGGGCATGGCACGCATGTGGCCGGGACGATCGCTGCTTTAAACAAT 161 S  I  G  V  L  G  V  A  P  S  A  E  L  Y  A  V  K  V  L  G 481 TCGATTGGCGTTCTTGGCGTAGCGCCGAGCGCTGAGCTATACGCTGTTAAAGTCCTAGGG 181 A  S  G  S  G  S  V  S  S  I  A  Q  G  L  E  W  A  G  N  N 541 GCGAGCGGTTCAGGTTCGGTCAGCTCGATTGCCCAAGGATTGGAATGGGCAGGGAACAAT 201 G  M  H  V  A  N  L  S  L  G  S  P  S  P  S  A  T  L  E  Q 601 GGCATGCACGTTGCTAATTTGAGTTTAGGAAGCCCTTCGCCAAGTGCCACACTTGAGCAA 221 A  V  N  S  A  T  S  R  G  V  L  V  V  A  A  S  G  N  S  G 661 GCTGTTAATAGCGCGACTTCTAGAGGCGTTCTTGTTGTAGCGGCATCTGGGAACTCAGGT 241 A  G  S  I  S  Y  P  A  R  Y  A  N  A  M  A  V  G  A  T  D 721 GCAGGCTCAATCAGCTATCCGGCGCGCTATGCGAACGCAATGGCAGTCGGAGCTACTGAT 261 Q  N  N  N  R  A  S  F  S  Q  Y  G  A  G  L  D  I  V  A  P 781 CAAAACAACAACCGCGCTAGCTTTTCACAGTATGGCGCAGGCCTTGACATTGTCGCACCC 281 G  V  N  V  Q  S  T  Y  P  G  C  L  D  L  K  T  Q  V  Q  T 841 GGGGTAAACGTGCAGAGCACATACCCAGGTTGTCTGGACCTGAAAACGCAAGTGCAAACC 301 P  Q  G  M  K  E  I  S  N  I  Q  V  G  D  L  V  L  S  N  T 901 CCGCAAGGCATGAAGGAAATCTCAAACATCCAAGTCGGTGACCTGGTGCTGTCGAATACC 321 G  Y  N  E  V  L  N  V  F  P  K  S  K  K  K  S  Y  K  I  T 961 GGCTATAACGAAGTGCTGAATGTTTTTCCGAAGAGCAAAAAGAAATCTTACAAGATCACG 341 L  E  D  G  K  E  I  I  C  S  E  E  H  L  F  P  T  Q  T  G 1021 CTGGAAGATGGCAAGGAAATTATTTGCAGCGAAGAACATCTGTTCCCGACCCAGACGGGC 361 E  M  N  I  S  G  G  L  K  E  G  M  C  L  Y  V  K  E  D  P 1081 GAAATGAATATCTCCGGCGGTCTGAAAGAAGGCATGTGTCTGTACGTCAAGGAAgatcct 381 N  G  M  S  D  K  I  I  H  L  T  D  D  S  F  D  T  D  V  L 1141 aatggtATGAGCGATAAAATTATTCACCTGACTGACGACAGTTTTGACACGGATGTACTC 401 K  A  D  G  A  I  L  V  D  F  W  A  E  W  C  G  P  C  K  M 1201 AAAGCGGACGGGGCGATCCTCGTCGATTTCTGGGCAGAGTGGTGCGGTCCGTGCAAAATG 421 I  A  P  I  L  D  E  I  A  D  E  Y  Q  G  K  L  T  V  A  K 1261 ATCGCCCCGATTCTGGATGAAATCGCTGACGAATATCAGGGCAAACTGACCGTTGCAAAA 441 L  N  I  D  Q  N  P  G  T  A  P  K  Y  G  I  R  G  I  P  T 1321 CTGAACATCGATCAAAACCCTGGCACTGCGCCGAAATATGGCATCCGTGGTATCCCGACT 461 L  L  L  F  K  N  G  E  V  A  A  T  K  V  G  A  L  S  K  G 1381 CTGCTGCTGTTCAAAAACGGTGAAGTGGCGGCAACCAAAGTGGGTGCACTGTCTAAAGG 481  Q  L  K  E  F  L  D  A  N  L  A  *  (SEQ ID NO: 1) 1441  CAGTTGAAAGAGTTCCTCGACGCTAACCTGGCCTAG (SEQ ID NO: 3)

In the map of iProtease NI, proProteaseS317 is the proProtease N-terminal part: 27 aa residue secretion signal of the pre-proProtease is removed; first methionine is added to the N-terminus; and proProtease aa residues are residues 28 to 316 (pre-proProtease numbering). GLFS-N is the N-intein. DPNG is asp-pro-asn-gly (SEQ ID NO: 5) linker between GLFS-N N-intein and Trx, and is shaded. Trx is the solubility enhancer thioredoxin domain from pET32 and is shown in bold letters.

Map of iProtease IC is as follows:

1 M  S  D  K  I  I  H  L  T  D  D  S  F  D  T  D  V  L  K  A 1 ATGAGCGATAAAATTATTCACCTGACTGACGACAGTTTTGACACGGATGTACTCAAAGCG 21 D  G  A  I  L  V  D  F  W  A  E  W  C  G  P  C  K  M  I  A 61 GACGGGGCGATCCTCGTCGATTTCTGGGCAGAGTGGTGCGGTCCGTGCAAAATGATCGCC 41 P  I  L  D  E  I  A  D  E  Y  Q  G  K  L  T  V  A  K  L  N 121 CCGATTCTGGATGAAATCGCTGACGAATATCAGGGCAAACTGACCGTTGCAAAACTGAAC 61 I  D  Q  N  P  G  T  A  P  K  Y  G  I  R  G  I  P  T  L  L 181 ATCGATCAAAACCCTGGCACTGCGCCGAAATATGGCATCCGTGGTATCCCGACTCTGCTG 81 L  F  K  N  G  E  V  A  A  T  K  V  G  A  L  S  K  G  Q  L 241 CTGTTCAAAAACGGTGAAGTGGCGGCAACCAAAGTGGGTGCACTGTCTAAAGGTCAGTTG 101 K  E  F  L  D  A  N  L  A  D  P  N  G  M  T  K  K  I  T  K 301 AAAGAGTTCCTCGACGCTAACCTGGCCgatcctaatggtATGacGAAGAAAATTacGAAG 121 I  E  E  L  D  E  R  E  L  I  D  I  E  V  S  G  N  H  L  F 361 ATCGAAGAACTGGATGAACGTGAACTGATTGACATCGAAGTTAGCGGCAACCATCTGTTT 141 Y  A  N  D  I  G  T  H  N  S  T  Y  A  S  L  N  G  T  S  M 421 TACGCGAATGACATTggGACCCACAACTCAACtTATGCCAGCTTAAACGGTACATCGATG 161 A  T  P  H  V  A  G  A  A  A  L  V  K  Q  K  N  P  S  W  S 481 GCTACTCCTCATGTTGCAGGTGCGGCCGCCCTTGTTAAACAAAAGAACCCATCTTGGTCT 181 N  V  Q  I  R  N  H  L  K  N  T  A  T  S  L  G  S  T  N  L 541 AATGTACAAATTCGAAATCATCTAAAGAATACGGCAACTAGTTTAGGAAGCACGAACTTG 201 Y  G  S  G  L  V  N  A  E  A  A  T  R  *   (SEQ ID NO: 2) 601 TATGGAAGCGGACTTGTTAACGCAGAAGCGGCAACGCGTTAA (SEQ ID NO: 4)

In the map of iProtease IC, Trx is the solubility enhancer thioredoxin domain from pET32, and is shown in bold letters. DPNG is asp-pro-asn-gly (SEQ ID NO: 5) linker between Trx and GLFS C-intein and is shaded gray. GLFS-C [M89Δ, L91T, L95T, L122G] is the “MTT” variant of the GLFS C-intein and is underlined. S317Protease is the proProtease C-terminal fragment starting at serine 317 (S317).

Example 3. Expression of Solubility Optimized NI and IC in E. coli

For expression in E. coli, nucleotide sequences of the solubility optimized NI and IC were cloned into the pET Duet1 (Novagen) expression vector downstream to the IPTG inducible T7 promoter. NI-DPNG-Trx was cloned between the NcoI and PstI sites, Trx-DPNG-MTT-IC[L122G] was cloned between the NdeI and KpnI sites. Plasmids were introduced into the E. coli strain BL21 Gold (DE3) (Invitrogen).

To express the proteins, overnight starter cultures grown in LB+Carbenicillin (100 mg/L) at 30° C. at 300 rpm were diluted 40-fold into fresh LB+Carb 100 mg/L, incubated further at 30° C. at 300 rpm. When cultures reached OD₆₀₀ 0.6, IPTG was added to a final conc. of 0.5 mg/L to induce expression and the t=0 time point samples were harvested. Aliquots (2 mL) were taken thereof at t=1.5, 3.0, 6.0 and 22.0 hrs. Cell were pelleted and lysed in 200 μL lysis buffer at 30° C., 300 rpm for 1 hour and lysates were split to two aliquots. Lysis buffer was 1:9 mix of [10× Fastbreak:mTSB buffer (150 mM NaCl, 50 mM Trisbase, 2 mM CaCl₂, pH=7.5, 1 mM DTT)]+0.2 L/mL Benzonase (Novagen). To determine the total protein profile, to 20 μL cell lysate 20 μL 2×SDS loading dye+5% βME was added, samples were heated at 95° C. for 5 min and a 5 μL aliquot was separated on 12% SDS/PAGE, and gels were Coomassie stained. To determine the soluble protein profile, lysates were spinned at 5000g for 5 min in a microfuge, the supernatant soluble fractions were harvested and a 20 μL aliquot was treated as above.

Most of the target proteins were produced during the first three hours of the induction in a time course typical to IPTG induced T7 promoter driven expression of recombinant proteins. Proteins expressed to comparable levels and predominantly accumulated to the soluble fraction. FIGS. 2A-2B illustrate expression of solubility optimized NI and IC in E. coli. FIG. 2A illustrates total protein profiles. FIG. 2B illustrates soluble protein profiles. In particular, FIG. 2B illustrates E. coli expression of solubility optimized NI and I^(C). Referring to FIGS. 2A-2B, expression was from the IPTG inducible T7 promoter of the pET Duet1 in E. coli BL21 Gold (DE3). Overnight cultures were diluted 40-fold into fresh LB+Carbenicillin (100 mg/L) and grown at 30° C., 300 rpm to OD 0.6. IPTG was added to a final conc. of 0.5 mg/L to induce expression and aliquots were taken at t=0, 1.5, 3.0, 6.0 and 22.0 hrs. Cells were harvested, lysed in 1/10^(th) culture volume of lysis buffer at 30° C., 300 rpm, 1 hr. Referring to FIG. 2A, to determine total protein profile the crude lysates were mixed with equal volume of 2×SDS loading dye+5% PME, heated at 95° C. for 5 min and 5 μL was separated on 12% SDS/PAGE and gels were Coomassie stained. Referring to FIG. 2B, to determine soluble protein profiles the crude lysates were clarified at 5000 g/5 min and the supernatant fraction was handled as above. It was observed that NI and IC predominantly expressed to the soluble fraction.

Example 4. Screening for Effectors of Dilution Induced iProtease Activity

The objective was to develop a liquid laundry detergent protease that can be stored in stable inactive state in the formulation and activated by dilution to water at the beginning of the wash cycle. The proof of concept demonstrated that Savinase can be split to two parts and expressed as intein modified inactive parts, and formulated them in liquid laundry detergent to restore activity by dilution into water. However, several challenges remained for the trans-splicing protease to meet application relevance, primarily in the robustness of dilution response to recover more than 80% activity (based on equal molar loadings with the intein unmodified enzyme), and in detergent storage stability in the induction competent state.

A major technical challenge was that while trans-splicing is a bimolecular, association driven and concentration dependent reaction, the application requires 400-fold dilution for induction that could counteract with post-dilution association of NI and IC for splicing. In addition for the trans-splicing to be robust, dilution induced splicing is expected to be fast and yield protease activity within minutes to be relevant for laundry detergent application. These requirements could be difficult to achieve by dilution when NI and IC are separate in the detergent, but conceivably could be better satisfied when the trans-splicing-parts are pre-associated but prevented from splicing.

Trans-splicing essentially progresses with the same mechanism as splicing (Perler F B, 2005), major difference is requirement for association of the intein parts. One possibility to associate trans-splicing precursors but prevent progression to splicing is to use splicing inhibitors, like Zn⁺⁺, Cu⁺⁺ or cistatin, that act in the post association step at the initiation of splicing (Nichols N M. et al, 2003; Sun P. et al, 2005: Zhang L. et al, 210; Zhang L. et al, 2011, all of which are incorporated by reference herein as if fully set forth). Although these inhibitors could satisfy requirement for controlled, dilution inducible splicing, they are not compatible with home use applications.

As an alternative, it was observed that the Detergent-1 suppressed iProtease activity in the formulations of NI and IC, but did not suppress activity of the intein unmodified Savinase suggesting that trans-splicing might be inhibited in the detergent. Modern liquid laundry detergents are complex formulations of a variety of ingredients including one or more ionic and nonionic surfactants, inorganic salts, electrolytes and adjuvants such as brighteners, perfumes and colorants and other compounds dispersed or dissolved in an aqueous medium that typically form structured liquids which could interact with formulated proteins in unpredictable ways. Inhibition may be the property of structured liquid or individual detergent components may also have suppression properties.

The effect of electrolytes on surface charge of proteins, and its isoelectric point, can be different in the presence of small electrolytes and for polymeric electrolytes Lyklema J, 2009; Martin-Molina A. et al., 2003; Besteman K., et al. 2004, all of which are incorporated by reference herein as if fully set forth). As opposed to monovalent salts, ion adsorption by polymeric ions by counterion interaction can even lead to effects such as charge inversion, and variance between isoelectric points measured via electrophoretic mobility, and the point of zero-surface charge (Besteman K. et al., 2004; Trulsson M. et al., 2006, all of which are incorporated by reference herein as if fully set forth).

Salts with monovalent ions were investigated, but also salts with large polyvalent/multivalent ions as detergent supplements for effecting dilution inducible iProtease activity of detergent formulated NI and IC, using detergent suppression and dilution induction assays. Detergent suppression measures activity of formulated NI and IC to yield iProtease in the detergent, dilution induction addresses the question whether suppression is reversible. To improve assay sensitivity, Detergent-2 have been selected. This detergent was compatible with NI and IC formulation, but had lower viscosity and showed lower detergent suppression activity than the Detergent-1. Supplements were selected for detergent compatibility and were industrial quality low cost chemicals. Concentrations were arbitrarily selected to be compatible with detergent formulation. The Detergent-2 was diluted to 50% (v/v) with deionized water with supplements to 2× concentration and no supplement in the control. 25 μL NI and 25 μL IC were then sequentially mixed to the detergents, and samples were exposed to suppression conditions overnight at 20° C. Samples were either diluted 20-fold to the corresponding detergent+supplement (detergent suppression assay) or diluted 20-fold to deionized water (dilution induction assay).

FIGS. 3A-3E illustrate effects of electrolytes and polyols on the detergent suppression and dilution induced activity of formulated trans-splicing NI and IC. Referring to these figures, supplements tested were as follows: sodium salt supplements (FIG. 3A), potassium salt supplements (FIG. 3B), ammonium salt supplements (FIG. 3C), charged polymeric salt supplements (FIG. 3D) and polyol supplements (FIG. 3E). The Detergent-2 was diluted to 50% (v/v) with deionized water and supplements were added to 2× concentration (e.g., 2M for 1M test). NI and IC were expressed in E. coli and clarified crude extracts were prepared as described in FIGS. 2A-2B. 25 μL NI and 25 μL IC were then sequentially mixed to the supplemented detergents, or to detergent without the supplement in the controls, and formulations were incubated to expose the samples to suppression conditions overnight at 20° C. In the detergent suppression assay, samples were diluted 20× to detergent with 2× supplement, except that control which was diluted 20× to detergent without supplement. In the dilution induction assay, 20× dilutions were made to deionized water. Protease activity was determined in three replicate samples, by mixing 100 μL of the diluted sample with 100 μl of FAAF-pNA substrate (500 μM) and absorbance was read at 400 nm in a kinetic assay for 60 min (FIG. 3E, Polyol supplements) or until absorbance in the highest activity sample reached near the maximum of the linear range of the assay at ˜2.8, and activities in detergent and water were graphed as shown in FIGS. 3A-3E.

A variety of salts, including alkali metals (lithium, sodium, potassium), ammonium with various counter ions including chloride, sulphate, nitrate, tartarate, succinate, disuccinate, imidodisuccinate, lactate, citrate, polyaspartae, polyacrylate increased iProtease activity upon dilution of the detergent formulated NI and IC to water. When dosed at different concentrations, the higher doses normally resulted in higher activity.

Polymeric salts that have more positive charge on a molar basis turned out to be potent enhancers of dilution inducible iProtease activity at a much lower concentration (0.02-0.0375M) than the monovalent salts (>0.25M). Sodium polyacrylate 7K (average MW 7300), and polyacrylate 2K (average MW 2100), carried, respectively about 100 and 30 sodium counter ions per molecule of polymer. Sodium polyaspartate, similarly carried about 35 of the sodium cations per molecule of polymer.

Electrolytes and polyelectrolytes listed, are non-limiting examples of chemicals that could possibly be suitable to control activity of detergent formulated NI and IC. Polyols, such as Neodol 25-7 represents yet another class of potential additives with similar properties.

Modern fabric detergents are concentrated structured liquids. Selection of a supplement for such a formulation would satisfy multiple criteria, such as suppression of activity of intein modified proteins in the undiluted concentrate, enhancement of enzyme activity upon dilution from intein modified parts, compatibility with the liquid formulation, fit-to-purpose as part of a household consumer product, including cost criteria.

Conceivably, supplements that may affect overall charge, charge distribution, hydration properties of the formulated trans-splicing proteins and/or alter protein association and crowding by other means in the detergent could have an effect on dilution inducible iProtease activity of the formulated trans-splicing NI and IC.

Detergent suppression and dilution induction assays described here enable quick screening for such effectors and could support formulation development for activity control of the intein modified proteins.

Example 5. Testing Effectors of Dilution Inducible iProtease Activity

Effectors Perform Similarly in Different Detergent Context

Supplements identified in the effector screen for activity enhancing effects in the in the Detergent-2 were found to perform similarly in the Detergent-1. FIGS. 4A-4B illustrate that effectors perform similarly in different detergent context. In particular, these figures compare dilution induction properties of three small molecule effectors, sodium nicotinate (90 mM), NaCl (1M) and KCl (500 mM) in the two detergents in quantitative protease assays. Assays were essentially the same as in the screen, but instead of cell lysates, purified proteins were used and activity was determined in a series of two fold dilutions in kinetic assays. Briefly, the trans splicing precursors in equal molar concentration were sequentially added to the salt supplemented detergents, incubated overnight at 20° C. to allow splicing to progress, then aliquots were serially diluted to assay buffer from 20 to 1280-fold (dilution induction assay), or 20-fold dilution were made to the corresponding supplemented detergent (detergent suppression assay) and protease activity was assayed with suc-FAAF-pNA (500 μM) substrate by measuring absorbance at 400 nm in a kinetic assay.

Referring to FIGS. 4A-4B, the Detergent-2 and Detergent-1 were supplemented either with sodium nicotinate (90 mM), or NaCl (1M) or with KCl (500 mM), NI and IC were added and dilution inducible iProtease activities were compared as follows:

Formulation: to 66.7 μL of Detergent-2, or Detergent-1 in a PCR tube, 20 μL of appropriate salt, or H₂O in the control, was added and mixed by pipetting and swirling. 4.42 μL of purified IC in mTSB buffer (50 mM Tris, 150 mM NaCl, 1 mM DTT, 2 mM CaCl₂, pH=7.5) was added into the salted detergent and after thorough mixing and stirring 8.86 μL of purified NI in mTSB buffer was mixed into the detergent+IC. NI and IC were combined at equimolar concentrations. Formulations were stored overnight at 20° C. to allow progression of splicing.

Detergent dilution assay was as follows. In a clear flat-bottomed 96 well plate (Corning 9017, Costar) row A wells were preloaded with 20 μL 1×BR buffer pH ˜9.0, and 160 μL H₂O. Rows B-G were preloaded with 10 dl 1×BR buffer pH ˜9.0, 90 μL H₂O. Twenty microliters of the formulation was added to row A, mixed by pipetting, then 100 μL of this 10× diluted sample was added to the 100 μL of water and buffer in row B and mixed. This results in 20× dilution. This 2× serial dilution process was repeated for rows C-G, discarding the excess 100 μL from row G for a final volume of 100 μL in each well. Final detergent concentration in row A, the 20-fold dilution, is 3.3%.

Detergent suppression assay (1:20 in det.) was as follows. In the same plate as above, row H was preloaded with 10 μl 1×BR buffer pH ˜9.0, 80 μL 100% detergent. 10 μL of the formulations were added individually to each well in row H and mixed. Final detergent concentration in the 20 fold diluted in the suppression assay is 43.3%.

For both assays (to the entire 96 well plate), 100 μL of the 2× suc-FAAF-pNA (500 μM in 20% DMSO) substrate was added and protease activity was assayed by reading absorbance at 400 nm at 30° C.

Detergent final concentration in the suppression assay is 43.3%, in the 20-fold water dilution assay is 3.3%. Referring to FIG. 4A, dilution inducible iProtease in the Detergent-2 supplemented either with sodium nicotinate (90 mM), or NaCl (1M), or KCl (500 mM). Referring to FIG. 4B, dilution inducible iProtease in Detergent-1 supplemented either with sodium nicotinate (90 mM) or NaCl (1M) or KCl (500 mM).

Referring to FIGS. 4A-4B, salt supplemented detergents invariably resulted in higher activity after dilution of formulated NI and IC, compared to their unsalted control. Referring to FIG. 4B, in the Detergent-1 dilution enhancement could be achieved without loss of suppression. However, possibly due to inherent differences in the iProtease activity suppression power of the two detergents, recovered total activities differed significantly in favor to the Detergent-2 (FIG. 4B). These results validated the utility of the detergent additive screen to uncover effectors of dilution inducible enzyme activity and suggested that at least some of the salts could be effective inducers of detergent formulated NI and IC independent from the detergent context.

Trans-splicing is initiated by association of the intein modified precursors. Studies on the DnaE split intein from Synechocystis sp. PCC6803 suggested that the split intein parts are disordered and undergo conformational transition from disorder to order upon association (Zheng Y. et al., 2012, which is incorporated herein by reference as if fully set forth). Recent report on the molecular mechanism of association of the model DnaE split intein of Nostoc punctiforme confirmed this hypothesis and showed that intein parts interact via a multi-step process initiated by electrostatic interactions followed by compaction and stabilization of the initially disordered intein parts onto a pre-folded region of the N-intein (Shah N H. et al 2013, which is incorporated herein by reference as if fully set forth). This mechanism of “capture and collapse” may be common in naturally split inteins and could be sensitive to effectors that influence charge, charge distribution and hydration properties of the molecules.

Therefore, the effect of changing of the ionic strength of salts identified in the effector screen on direct control dilution inducible iProtease activity independent of the detergent context and tested the KCl was examined.

Example 6. KCl have Dual Roles, Promotes Association of Splicing Precursors and Suppress Splicing

Trans-splicing requires association of precursors to initiate a multi-step splicing reaction that eventually yields the active enzyme (Wu H. et al. 1998; Martin et al, 2001; Perler F B. 2005, all of which are incorporated herein by reference as if fully set forth). To have a better understanding at what stage KCl could play a role, KCl (0.125, 0.25, 0.5, 1.0 and 2.0 M) were added to the splicing precursors before the initiation of splicing keeping NI and IC constant and added 2M KCl after 2 hrs. incubation of the splicing mix after completion of splicing.

Cell lysates of NI and IC were separately treated with increasing conc. of KCl from 0.125, 0.25, 0.5, 1.0 and 2.0 M and incubated for 10 min/RT before precursors were mixed and incubated for another 2 hrs./RT to allow progression of splicing in increasing conc. of the salt. Samples were split to two aliquots, one was diluted to BR buffer pH ˜9.0 (dilution induction assay) the other was diluted to high salt (2M KCl in BR buffer pH ˜9.0; salt suppression assay) and iProtease was assayed.

FIGS. 5A-5B illustrate that KCl reversibly inhibits iProtease activity in aqueous buffer. Referring to these figures, 4M KCl was 2-fold serially diluted from 4M to 0.03125M. Two sets of 15 μL aliquots were dispensed to PCR tubes. To one set, 15 μL clarified NI cell lysates were added, to the other set 15 μL clarified IC cell lysates were added and tubes were incubated at room temp for 10 min. Presalted NI and IC in the same conc. of KCl were mixed and incubated at room temperature for 10 min. FIG. 5A illustrates dilution induction assay. Referring to this figure, constant amounts of (NI+IC) premixes in serial dilutions of KCl were 20-fold diluted to BR buffer and assayed for iProtease activity as follows: 5 μL of (NI+IC) premixes were added to 95 μL BR buffer pH ˜9.0, then 100 μL of suc-FAAF-pNA (500 μM) substrate was added and absorbance was read at 400 nm at 30° C.

FIG. 5B illustrates salt suppression assay. Referring to FIG. 5B, constant amounts of (NI+I^(C)) premixes in serial dilutions of KCl were 20-fold diluted to 2M KCl and assayed for iProtease activity as follows. 5 μL of (NI+IC) premixes were added to 95 μL 2M KCl in BR buffer pH ˜9.0, then 100 μL of suc-FAAF-pNA (500 μM) substrate was added and absorbance was read at 400 nm at 30° C. It was observed that dilution induction assay recapitulated the dilution induced salt enhancement effects in the detergent contexts. Referring to FIG. 5A, it was observed that the more salt was added to the precursors before mixing the higher the iProtease activity was in the dilutions. Salt suppression assays in 2M KCl revealed another correlation between salt concentration and activity. In samples where salt concentrations were initially high before mixing of the precursors (0.5-2.0 M KCl) and maintained high in the assay (2.0 M KCl), iProtease activity was inhibited. In samples where salt concentration were initially low before mixing the precursors (0.015-0.025 M KCl), iProtease activities increased in the high salt (2M KCl), albeit were below than in their corresponding aliquots diluted to buffer (compare enzyme activities of the same salt concentration buffer in FIG. 5A with FIG. 5B).

There appears to be a high salt regulated enzyme activity switch that requires pretreatment of the precursors with high salt (0.5-2.0 M KCl) before initiation of splicing and dilution of the salt to below 0.5 M KCl to recover activity. Adding high salt (2.0 M KCl) late in the splicing reaction is largely ineffectual, but is inhibitory when kept at high level (≥0.5 M KCl) throughout the splicing reaction.

Since trans-splicing requires association of precursors for initiation of splicing, it was hypothesized that KCl may effect this association in two different ways: increase association but suppress splicing, reversibly in a concentration dependent manner.

Association of trans-splicing proteins is a concentration driven reaction which conceivably would be reduced by dilution of the precursors. To determine whether 2M KCl could promote association, precursors were combined in (NI+IC) premix in 2M KCl then sequentially diluted it in 2M KCl. Alternatively, NI and IC were first separately diluted in 2M KCl, then combined the sequentially diluted NI with the sequentially diluted IC to create NI−IC mixes. Samples were then assayed for dilution inducible iProtease.

FIGS. 6A-6B illustrate that high concentration of KCl promotes association of the splicing precursors. FIG. 6A illustrates iProtease activity in serial dilutions of the high salt associated (NI+IC) premix in the BR buffer. FIG. 6B illustrates iProtease activity in mixes of separate serial dilutions of NI and IC (NI−IC) in the BR buffer.

Referring to FIG. 6A, the (NI+IC) premixes resulted in iProtease activity in all the 8 serial dilutions, and activity was proportional with the sequentially reduced amounts of NI and IC in the premix. Referring to FIG. 6B, in contrast, in dilutions of the NI−IC mixes iProtease activity quickly dropped below detection level after three dilution steps, indicating that NI and IC concentrations dropped below the level necessary for association and initiation of splicing. These results are consistent with the interpretation that pretreatment of the splicing precursors with high concentration of KCl promotes association of the splicing precursors in the (NI+IC) premix. Referring to FIGS. 6A-6B, assays were set up as follows. Three sets of tubes were set up: to a set of 8 PCR tubes, labeled as (NI+IC)1-8, 40 μL 2M KCl were dispensed. To two sets of 8 PCR tubes labeled NI 1-8 and IC 1-8, respectively, 20 μL 2M KCl were aliquoted.

(1) 50 μL clarified NI lysate was mixed with 50 μL 4M KCl and 50 μL of clarified IC lysate was mixed with 50 μL 4M KCl and incubated at RT for 10 min

(2) 20 μL of the pre-salted NI and 20 μL of the pre-salted IC were mixed to tube (NI+IC)1, For controls 20 μL pre-salted NI was added to tube NI.1; and 20 μL pre-salted IC to tube IC.1 and mixed.

(3) 40 μL of (NI+IC) 1 was then added to tube marked (NI+IC) 2 and mixed; 20 μL of NI.1 was added to NI.2 tube, and 20 μL of IC.1 was added to IC.2 tube, and mixed. These steps were repeated to create stepwise dilutions of up to (NI+IC) 1-8, NI 1-8 and IC 1-8. Then NI 1 was mixed with IC 1, NI 2 with IC 2 to create the NI−IC 1-8 set.

(4) (NI+IC) and NI−IC sets were incubated at RT for 10 min.

(5) To assay dilution inducible iProtease activity, 51 μL aliquots of the (NI+IC) or NI−IC were mixed with 95 μL BR buffer pH ˜9.0 then 100 μL of suc-FAAF-pNA (500 μM) substrate was added and absorbance was read at 400 nm in a kinetic assay at 30° C.

FIG. 6A illustrates iProtease activity in serial dilutions of high salt associated (NI+IC) premix in dilutions to BR buffer.

FIG. 6B illustrates iProtease activity in mixes of separate serial dilutions of NI and IC (NI−IC) in BR buffer.

To determine whether iProtease is generated by splicing or via association driven protein complementation, splicing was evaluated. Due to concerns that the splice product may be difficult to detect because it has protease activity and may auto-degrade. Therefore, to protect the splice products from proteolytic auto-degradation, alanine was mutated the serine catalytic residue of the iProtease in the IC (S326A). Splicing was tested by mixing equal volumes of crude lysates of E. coli expressed splicing precursors. Two mixes were made, with or without salt treatment of the precursors. Salt treatment was by mixing separately equal volumes of NI and IC with equal volumes of 2M KCl, before mixing the precursors. In the unsalted sample, equal volume of H₂O was added to each precursor before mixing. The unsalted and salted mixes of (NI+IC) and (NI+IC^(S326A)) were quickly diluted to aqueous buffer and aliquots were taken at t=0, 1 min and 30 min to 2×SDS loading dye+5% μME, and total protein profiles were analyzed on Coomassie stained 12% SDS/PAGE. Residual KCl concentration in salt pretreated (NI+IC) mix was 200 mM after dilution to aqueous buffer.

In dilutions of the unsalted (NI+IC) and (NI+IC^(S326A)), a new protein species accumulated at the expected size for the splice product, late in the splicing reaction at t=30 min. In the protease inactivated salted precursor mix of (NI+IC^(S326A)), splice product was instantly visible at t=0 and stayed at the same high level, and there were no sign of proteolytic degradation. In the salted precursor mix of wild type (NI+IC), splice product detection was weakened due to instant protein degradation, and most of the proteins were degraded by t=30 min. These observations are consistent with the interpretation that mixing of the precursors results in splicing and that pretreatment of the precursors with equal volume of 2M KCl before mixing results in splicing and ultra-fast protease activity.

FIGS. 7A-7B illustrate that a coomassie gel shows splicing after mixing the splicing precursors NI and IC. Referring to these figures, splicing was evaluated after mixing of the splicing precursors and following proteins profiles over 30 min on Coomassie stained 12% SDS/PAGE. To protect the splice products from proteolytic auto-degradation the serine catalytic residue in the IC were alanine mutated to create (IC^(S32A)). 2× concentrated cell lysates of NI, IC and the IC^(S326A) were prepared as shown in FIG. 2A (total protein profiles) and FIG. 2B (soluble protein profiles). To prepare the salted premix, NI or IC or IC^(S326A) were separately mixed with equal volume of 2M KCl. After 10 min at RT, 25 μL of NI in 1M KCl was mixed with 25 μL IC in 1M KCl, and in a separate sample 25 μL NI was mixed with 25 μL IC^(S326A). Immediately after mixing, 20 μL of the (NI+IC) and (NI+IC^(S326A)) were diluted with 70 μL deionized water supplemented with 10 μL BR buffer pH ˜9.0, and at the t=0 time point 20 μL aliquots were immediately taken into 20 μL 2×SDS loading dye+5% μME, and samples were heated at 95° C./5 min. Further aliquots were taken at 1 min and at 30 min after dilution and were processed similarly. Residual KCl concentrations in the diluted samples were 200 mM, before adding the loading dye. 15 μL samples were separated on 12% SDS/PAGE and the gels were stained with Coomassie. To prepare the unsalted premixes, samples were handled by the same protocol but instead of 2M KCl, H₂O was added to the 2× concentrated cell lysates. FIG. 7A illustrates protein profiles after dilution of unsalted premix to aqueous buffer. Referring to this figure, 30 min after mixing of precursors to initiate splicing a new protein species accumulated in both (NI+IC) and NI+IC^(S326A)) at the expected size for the splice product. FIG. 7B illustrates protein profiles after dilution of salted premix to aqueous buffer. Referring to this figure, in the (NI+IC) samples protein degradation was instantly visible after initiation of splicing in the t=0 time point and by t=30 min most of the proteins were degraded. In the protease inactivated (NI+IC^(S326A)) premix, there was no visible protein degradation and large amounts of splice product was detectable at t=0. Positions of the NI and IC and IC^(S32)6A are marked. Position of the splice product is marked by arrow.

KCl appeared to be a potent effector of NI and IC, promoted association of the splicing precursors into a splicing inactive form, suppressed iProtease activity at concentration higher than 0.5 M, which could be reversed by reducing KCl concentration bellow 0.5 M. By this measures, KCl is an inhibitor and conditional regulator of trans-splicing regulated iProtease.

Because of the shared structural features including disordered structures and charge distribution between the two intein halves and shared mechanisms for association among trans-splicing inteins, the high salt controlled association of split-intein modified protein fragments possibly is not restricted to NI and IC, but could be applicable to other split-intein modified proteins, and could have use in assembling two- or more trans-intein modified protein fragments for controlled activity. (Zheng Y. et al., 2012; Shah N H. et al 2013, Aranko A S. Et al., 2013, all of which are incorporated by reference as if fully set forth). Salt based conditional regulation, as exampled by the KCl regulated iProtease, could provide a simple and possibly more generic approach to regulate trans-splicing intein modified proteins for controlled activity. A major advantage of this strategy is reliance on wild type trans-splicing inteins and avoidance of the normally difficult genetic engineering of trans-splicing inteins for conditional regulation of target protein activity (Mootz et al, 2003; Selgrade et al. 2013, both of which are incorporated herein by reference as if fully set forth).

Effector screens for dilution inducible iProtease showed that compounds of diverse chemical nature, electrolytes, polyelectrolytes, polyols, hydrotropes (glycerol, monopropylene glycol, nonionic ex Shell (Neodol) could be effectors. Conceivably, chemicals with similar physicochemical characteristics could also perform similarly. Because effectors appear to be more numerous than splicing inhibitors, Zn⁺⁺, Cu⁺⁺ or cistatin and have diverse chemistry, possibly they could be better tailored to the needs of specific applications, including extreme chemical conditions, when activity of the target protein need to be conditionally regulated (Nichols N M. et al, 2003; Sun P. et al, 2005; Zhang L. et al, 210; Zhang L. et al, 2011, all of which are incorporated by reference as if fully set forth).

Examples 7-16 describe using an effector of detergent dilution inducible iProtease activity in liquid laundry detergent formulation for stable storage and dilution inducible efficient recovery of protease activity. The examples describe formulation of KCl stabilized (NI+IC) premixes to aqueous solutions and to liquid laundry detergents for stable storage and efficient recovery of protease activity quickly, without loss of cleaning efficiency.

Example 7. Benchmarking of Dilution Induced iProtease to Savinase

Purified NI stock was 45 mg/mL (855.9 micromolar) in mTSB buffer (50 mM Tris, 150 mM NaCl, 1 mM DTT, 2 mM CaCl₂, pH ˜7.5). Purified IC stock was 33.58 mg/mL (1460 micromolar) in mTSB buffer. To benchmark iProtease activity to 1% (vol/vol) Savinase (˜103 g/L, Novozymes), each of purified NI and IC was used at 38.1 μmolar concentration. (NI+IC) premix for 7×200 μL volume formulations was made as follows: to 62.3 μL NI in Eppendorf tube 6.23 μL 100 mM DTT was added. After 10 min at room temperature (RT), equal volume (68.53 μL) of 4M KCl was added by mixing and the sample was incubated for 10 min at RT. To 36.4 μL IC in Eppendorf tube 3.64 μL of 100 mM DTT was added and mixed. After 10 min at RT, equal volume (40.0 μL) of 4 M KCl was added and the sample was incubated at RT for 10 min. To prepare 4× concentrated (NI+IC) premix in 2M KCl, 137 μL of NI in 2M KCl was mixed with 80 μL IC in 2M KCl, mixed by pipetting. After 10 min at RT, 133 μL of 2M KCl was added, that resulted in 350 μL (NI+IC) premix (4×). In aqueous formulations 50 μL of 4× concentrated (NI+IC) premix was added to 150 μL deionized water+KCl; KCl final concentration was 1M. When formulations were made to detergent, 50 μL of 4× concentrated (NI+IC) premix was added to 150 μL of KCl supplemented detergent. KCL final concentrations in the formulations were 1M, NI and IC final concentrations were 38.1 μmolar each.

Savinase (˜103 g/L, inhibitor stabilized stock) was KCl treated essentially as NI and IC as follows. Savinase was diluted 3-fold in mTSB buffer. To 60 μL Savinase in mTSB, 190 μL deionized water and 250 μL of 4 M KCl was added to prepare 500 μL of 4× concentrated stock in 2M KCl, sufficient for 10×200 μL formulations of 1% (v/v) Savinase. In aqueous formulations, 50 μL of 4× Savinase in 2M KCl premix was added to 150 μL deionized water+KCl; KCl final concentration was 1M. When formulations were made to detergent, 50 μL of 4× Savinase in 2M KCl premix was added to 150 μL of the KCl supplemented detergent. Savinase was 1%, KCL final concentrations in the formulations were 1M.

Protease assays were performed in 96 well plates (Corning 9017, Costar, clear flat bottom). Row A wells were preloaded with 20 μL 1×BR buffer pH ˜9.0, and 160 μL H₂O. Rows B-H were preloaded with 10 μl 1×BR buffer pH ˜9.0, 90 μL H₂O. 20 μl of the formulation was added to row A, mixed by pipetting, then 100 μL of this 10× diluted sample was added to the 100 μl buffer and water in row B and mixed. This results in 20× dilution. This process of 2× serial dilutions was repeated for rows C-H. This is the detergent dilution assay. To 100 μL samples in the wells 100 μL of a 2× suc-FAAF-pNA (500 μM in 20% DMSO) substrate was added and iProtease activity was assayed by reading absorbance at 400 nm at 30° C.

FIGS. 8A-8B illustrate benchmarking of dilution inducible iProtease activity to 1% Savinase. Referring to these figures, it was observed that iProtease (FIG. 8A) and Savinase (FIG. 8B) have comparable dilution activity profiles. Results demonstrated robust activity and ultra-fast recovery of iProtease activity with above 95% efficiency.

Example 8. KCl Stabilized (NI+IC) Premix had No Protease Activity

iProtease activity was benchmarked to 1% (v/v) Savinase. Formulation of (NI+IC) and Savinase to 1M KCl aqueous buffer was the same as in Example 1, but enzyme activity was assayed in 2M KCl as follows: In a clear flat-bottomed half-volume 96 well plate, row A wells were preloaded with μL 1×BR buffer pH ˜9.0, 50 μl 4 M KCl, and 35 μL H₂O. Rows B-H were preloaded with 5 μl 1×BR buffer pH ˜9.0, 25 μL 4 M KCl, and 20 μL H₂O. 5 μl (NI+IC) formulation was added to row A, mixed by pipetting, then 50 μL of this 20× diluted sample was added to the 50 μl salt, buffer, and water in row B and mixed. These resulted in 40× dilution. This process of 2× serial dilutions was repeated for rows C-H. All samples were diluted an addition 2× by adding 50 μL 500 μM suc-FAAF-pNA (in 20% DMSO) substrate, yielding samples diluted from 40× in row A to 5120× in row H. Protease activity was assayed by reading absorbance at 400 nm at 30° C. FIGS. 9A-9B illustrate that KCl stabilized (NI+IC) premix has no enzyme activity. FIG. 9A illustrates iProtease activity of the 80-fold diluted (NI+IC) premix. FIG. 9A illustrates Savinase. It was observed that 1M KCl inhibited protease activity of (NI+IC) premix but did not inhibit protease activity of the intein unmodified reference enzyme, Savinase.

Example 9. KCl Stabilized (NI+IC) Premix can be Stored in Aqueous Buffer without Significant Loss of Activity

4× concentrated (NI+IC) premix was prepared in 2M KCL as in Example 1 and stored at 4° C. 4× (NI+IC) premix was formulated to aqueous buffer at t=0 and after 8 weeks storage at 40° C. and assayed for iProtease activity as described for Example 8. FIGS. 10A-10B illustrate storage stability of KCl stabilized (NI+IC) premix in aqueous buffer. Referring to these figures, comparison of dilution inducible activities at t=0 with t=8 weeks indicated no loss of dilution inducible iProtease activity. The slightly higher activity at t=8 possibly due to ambient temperature difference in the assay. Retention of inducible activity showed high storage stability.

Example 10. KCl Stabilized (NI+IC) Premix can be Formulated to Detergent-1, without Loss of Dilution Inducible Activity

This assay evaluated dilution induction efficiency of Detergent-1 formulated KCl stabilized (NI+IC) premix. Purified (NI+IC) premix was prepared at benchmarking concentrations and aliquots were formulated either to aqueous buffer with 1 M KCl or into 50% Detergent-1 supplemented with 1M KCl, as described in Example 8. iProtease activity was measured in sequential dilutions from 80- to 10240-fold dilutions to aqueous buffer. FIGS. 11A-11B illustrate that KCl stabilized (NI+IC) premix can be formulated to Detergent-1 without loss of dilution inducible activity. FIG. 11A shows dilution activities from 1 M KCl aqueous buffer. FIG. 11B shows dilution activities from 50% Detergent-1-1M KCl. Detergent-1 formulated premix retained full dilution inducibility. Dilution induction was ultra-fast and highly efficient.

Example 11. KCl has Dual Roles in Detergent Formulation: Stabilize (NI+IC) Premix for Formulation and Maintain Stability in Detergent

FIG. 12 illustrates comparison of alternative protocols to detergent formulate NI and IC and evaluated formulations for long term stability. Two formulation protocols as follows were compared: 1) formulation by sequential mixing of unsalted NI and IC to the detergent (detergent+NI+IC) and 2) formulation of KCl stabilized (NI+IC) premix to detergent. Detergent-1 was used at 60% (v/v) in two formats, either without supplement (−), or KCl supplement was added to 1M final concentration (+). Purified NI and IC were each used at benchmarking conc. to 1% (v/v) Savinase, at 38.1 μmolar concentration each. (NI+IC) premix was prepared and formulated to the detergent essentially as described in Example 7. Formulations were stored at 37° C. under accelerated ageing conditions and storage stabilities were tested by assaying retention of dilution inducible iProtease activity over 8 weeks at t=0, 1, 3, 6 and 8 weeks in storage. Dilution inducible activity was assayed in sequential dilutions to assay buffer, from 40- to 5120-fold dilutions as described in Example 7. iProtease activities at the 2 min time point reads of the 1:1280-fold dilutions were normalized to dilution induced iProtease activity of the (NI+IC) premix in detergent without salt at t=0 and were plotted.

Results confirmed advantage of formulating 1M KCl stabilized (NI+IC) premix over formulation by sequential mixing of NI and IC to the detergent, and showed the benefit of having 1M KCL supplement in the detergent for long term storage. In the formulation made by sequential mixing of NI and IC into detergent without salt supplement, iProtease activity was low and quickly declined. Supplementing the detergent with 1M KCl boosted activity approximately 3-fold but inducible activity gradually declined over time.

Formulation of (NI+IC) premix resulted in high initial activity at t=0, but storage stability was weak in the un-supplemented detergent, and retention of dilution inducible activity gradually declined by approximately 50% over 8 weeks. Best results were obtained when the KCl stabilized (NI+IC) premix was formulated to 1M KCl supplemented detergent. This formulation retained dilution inducible full activity over 3 weeks and approximately 80% activity over 8 weeks, indicating that 1M KCl is important both in the formulation of trans splicing precursors and as a detergent additive to maintain reversible inhibition of dilution inducible activity.

FIG. 12 illustrates that KCl has dual roles in detergent formulation: stabilize (NI+IC) premix for formulation and maintain stability in detergent.

Example 12. iProtease Stability was Comparable with Savinase in Detergent-1 Under Accelerated Ageing Conditions

Savinase was used at 1% (v/v) and formulated to 60% Detergent-1 supplanted with 1M KCl. Purified NI and IC were used at equimolar concentration to 1% (v/v) Savinase, at 38.1 molar concentration each. (NI+IC) premix was prepared and formulated to 60% Detergent-1 supplemented with KCl to 1 M final concentration of the KCl, as described in Example 11. Formulations were stored at 37° C. under accelerated ageing conditions and storage stability was tested by assaying retention of dilution inducible iProtease activity over 8 weeks at t=0, 1, 3, 6 and 8 weeks in storage. FIG. 13 illustrates iProtease storage stability in Detergent-1 is comparable with, Savinase under accelerated ageing conditions. Referring to this figure, protease activities were assayed in sequential dilutions to assay buffer as described before and iProtease and Savinase activities at the 2 min time point reads of the 1:1280-fold dilutions were normalized each to its t=0 as 100% and residual activities were graphed.

Residual activity profiles of iProtease were comparable with Savinase. Both formulations retained approximately 75-80% activity under accelerated ageing conditions after 8 weeks at 37° C. Results demonstrated that the trans-splicing intein technology can be effectively used for protease stabilization in liquid laundry detergent.

Example 13. KCl Stabilized (NI+IC) Premix was Compatible with Four Different Types of Detergents

This assay evaluated four different types of liquid laundry detergents for dilution inducible iProtease activity: Detergent-1, Detergent-2, Detergent-3 and Detergent-4. Detergents were either enzyme free formulations (Detergent-1, Detergent-4) or commercial brand detergents (Detergent-2, Detergent-3) with formulated protease that were inactivated by heat treatment.

iProtease was benchmarked to 1% (v/v) Savinase. Preparation of KCl stabilized (NI+IC) premix and formulations to 1M KCl supplemented 50% detergents were made as described in Example 7. Savinase was formulated at 1% (v/v) to 1M KCl supplemented 50% detergent using the same protocol as in Example 8. FIG. 14 illustrates that detergent formulated KCl stabilized (NI+IC) premix retains full dilution inducible activity in different types of detergents: Detergent-1, Detergent-2, Detergent-3 and Detergent-4. Referring to this figure, protease activities were assayed in sequential dilutions to assay buffer as described before and iProtease and Savinase activity reads of the 2560-fold dilutions at 2 minutes were graphed. iProtease and Savinase activities were comparable across all the four detergents, indicating that dilution induction of KCl stabilized (NI+IC) premix was largely independent from the detergent.

Example 14. Stain Removal Efficacy of iProtease was Comparable with the Intein Unmodified Enzyme Savinase in Four Liquid Laundry Detergents

Formulations made into four different types of detergents and assayed for protease activity (Example 13) were evaluated for stain removal activity as follows:

Soiled cloth standard was as follows. Swiss Standards Agency test fabric, EMPA 117 was used for the tests. The fabric was a polyester/cotton blend, 65/35, soiled with blood/milk/ink. Approx weight: 165 grams/meter² (4.86 ounces/yard²). Approximate width was 58 inches (147 cm). Circular disks of the fabric were punched out to fit in a standard 96-well microplate. The punch size and the fabric circle diameter was 5.56 mm (7/32; 0.22 inch), with an area of 24.25 mm square.

Reagents were as follows: 120FH buffer (French Hardness Units, 10×) 8 mM calcium chloride (0.887 g CaCl₂)+4 mM magnesium chloride (0.813 g MgCl₂.6H₂O) in H₂O (1000 mL); 200 mM boric acid (10×). 12.37 g boric acid in 1 L H₂O; pH to 9.0 with NaOH; and 1.25% detergents in H₂O.

Washing:

Washings were run on three replicate fabric disks. Formulated enzyme (iProtease and Savinase) dilutions were made in 50% detergent stock (detergent in dH₂O). 1:40 dilutions with dH₂O were made for each formulation. Reagents were added to the flat bottom 96 well plate containing a blood stained cloth disk in the following order: 1.25% detergent in H₂O 20 μL; 200 boric acid 20 μL; 120 FH 6 μL; H₂O 134 μL; and 2.5% formulation in H₂O 20 μL. The assay total volume was 200 μL. The 96 well plate was covered with foil and incubated for 1 hour shaking at 200 RPM at 37° C. The foil was removed and 100 μL of the supernatant was pipetted before removing all liquid.

Rinse:

the plate with stained disks was refilled with 200 μl dH₂O per well, and sealed with foil. Wash was performed with a Multitron shaker set to 900 rpm. The sealed plate was placed on the platform and the door was closed, allowing the shaker to spin up until it reached 890 rpm (about 60 seconds) before removing the plate. The rinse water was removed and discarded. A total of three washes were performed.

White Light Reflectance Reading.

The test fabric circles had a diameter of 5.56 mm (area 24.25 mm square). Of this the inner circle used for measuring white light reflectance had a diameter of about 4.16 mm corresponding to 40 pixels (area 13.64 mm square, corresponding to 1264 pixels). While light reflectance was quantified via a 16 bit/pixel grayscale image corresponding to the measurement area. The imager was pre-normalized for any source light variation over the imager pixels.

FIG. 15 illustrates stain removal efficacy of detergent formulated iProtease is comparable with Savinase in four laundry detergents. This figure shows white light reflectance of washed EMPA 117 (blood/milk/ink stained) fabrics. Each graph is the average of the reflectance of three washed fabric. iProtease stain removal was comparable with Savinase in each of the detergent tested.

Example 15. Stability of Dilution Inducible iProtease Activity in Three Detergents Under Accelerated Ageing Conditions

Detergents were: Detergent-1, Detergent-2 and Detergent-3. For benchmarking 1% (v/v) Savinase was used, but instead of formulating the inhibitor stabilized form, the inhibitor was first removed by three steps of overnight dialysis of 0.5 mL Savinase against 5 L mTSB buffer at 4° C. using a Tube-O-Dialyzer Medi (4000 Da; GBiosciences). Volume of dialyzed Savinase in mTSB were adjusted to 1.5 mL, and 3 μL dialyzed aliquot treated with equal volume of 4M KCL was used to formulate 100 μL detergent to get 1% (v/v) of the Savinase. Sample handling was essentially the same as in Example 8, except that formulations were made to 65% detergents supplemented with KCL to 1M final conc.

Purified NI and IC were used at equimolar conc. to 1% (v/v) dialyzed Savinase, at 38.1 molar concentration each. (NI+IC) premix in 2M KCl was prepared as described in Example 7, and formulations were made to 65% detergents supplemented with KCl to 1M final conc.

Detergent formulations were stored under accelerated ageing conditions at 37° C. Residual protease activities were assayed at five time points, at t=0, 1, 2, 3, and 4 weeks, in serial dilutions to assay buffer as described before. The 2 min reads of 1:2560-fold dilutions of each formulation was normalized to the t=0 as 100% and graphed. FIG. 16 illustrates stability of dilution inducible iProtease activity in three detergents under accelerated ageing conditions. Data show that iProtease retained more activity than the inhibitor-stabilizer free Savinase, under accelerated ageing conditions at equal dosing of the proteases in each of the three detergents tested.

Example 16. Stability of Stain Removal Activity in Three Detergents Under Accelerated Ageing Conditions

Formulations made for Example 15 were stored under accelerated ageing conditions at 37° C., and were evaluated for stain removal activity at five time points, at t=0, 1, 2, 3, and 4 weeks in storage.

The blood/milk/ink stained fabric of EMPA 117 was used in wash tests as described in Example 15. FIG. 17 illustrates stain removal stability under accelerated ageing conditions in three detergents. Three replicate washes were performed from each formulation at each time point. Referring to this figure, white light reflectance of the washed EMPA117 fabrics were normalized to their corresponding t=0 samples and were graphed.

Referring to FIG. 16, iProtease retained full stain removal activity in each of the three detergents, consistent with the stability of dilution inducible activity. Savinase, which without the stabilizer has lost between ˜25-70% of initial enzyme activity also showed full stain removal activity. Possibly, proteases were dosed higher than necessary to achieve maximum stain removal within the confines of this assay.

Example 17. Division of Thermophilic Cis-Inteins into Trans-Inteins

The thermophilic cis-inteins were artificially split into trans-splicing intein pairs. Amino acid sequences of artificially split intein pairs are listed below by name of the cis intein as in the New England Biolab Intein Database (http://www/neb/com/neb/inteins.html) followed by the splicing domain specifier (—N or —C). Abbreviated identifier of split intein parts are in parenthesis.

-   -   1. Cbu_DnaB (12)N-intein (SEQ ID NO: 16) and Cbu_DnaB         (12)C-intein (SEQ ID NO: 17)     -   2. Mja_GF-6P(44)N-intein (SEQ ID NO: 18) and Mja_GF-6P-C         (44)C-intein (SEQ ID NO: 19)     -   3. Mja_Hyp-1-N(#46-N) (SEQ ID NO: 20) and Mja_Hyp-1-C(#46-C)         (SEQ ID NO: 21)     -   4. Mja_IF2-N(#47-N) (SEQ ID NO: 22) and Mja_IF2-C(#47-C) (SEQ ID         NO: 23)     -   5. Mja_Pol-1-N(#50-N) (SEQ ID NO: 24) and Mja_Pol-1-C(#50-C)         (SEQ ID NO: 25)     -   6. Pab_CDC21-1-N(#79-N) (SEQ ID NO: 26) and Pab_CDC21-1-C         (#79-C) (SEQ ID NO: 27)     -   7. Pab_IF2-N(#81-N) (SEQ ID NO: 28) and Pab_IF2-C(#81-C) (SEQ ID         NO: 29)     -   8. Pab_VMA-N(#92-N) (SEQ ID NO: 30) and Pab_VMA-C(#92-C) (SEQ ID         NO: 31)     -   9. Pho_IF2-N(#103-N) (SEQ ID NO: 32) and Pho_IF2-C(#103-C) (SEQ         ID NO: 33)     -   10. Pho_VMA-N(#110-N) (SEQ ID NO: 34) and Pho_VMA-C (#110-C)         (SEQ ID NO: 35)     -   11. Rma_DnaB-N(#116-N) (SEQ ID NO: 36) and Rma_DnaB-C (#116-C)         (SEQ ID NO: 37)     -   12. Sru_DnaB-N(#123-N) (SEQ ID NO: 38) and Sru_DnaB-C (#123-C)         (SEQ ID NO: 39)     -   13. Tag_Pol-1_Tsp-TY_Pol-1-N(#128-N) (SEQ ID NO: 40) and         Tag_Pol-1_Tsp-TY_Pol-1-C(#128-C) (SEQ ID NO: 41)     -   14. Ter_RIR1-4-N(#135-N)(SEQ ID NO: 42) and Ter_RIR1-4-C         (#135-C) (SEQ ID NO: 43)     -   15. Tko_IF2-N(#143-N) (SEQ ID NO: 44) and Tko_IF2-C(#143-C) (SEQ         ID NO: 45)     -   16. Tth-HB27_DnaE-2-N(#150-N) (SEQ ID NO: 46) and         Tth-HB27_DnaE-2-C(#150-C) (SEQ ID NO: 46)

The trans-splicing inteins described herein were further tested using bi-cistronic expression cassettes for restoration of protease activity.

Example 18. Construction of Bi-Cistronic Expression Cassettes to Test Artificially Split Inteins in Savinase for Restoration of Protease Activity

Savinase was split to two parts at the serine 317 aa residue (S317) to create proSav-N and Sav-C exteins. FIG. 18 illustrates a bi-cistronic expression cassette. Referring to FIG. 18, trans-splicing intein-N(I^(N)) was fused in frame with the C-termini of proSav-N creating NI, while trans-splicing intein-C (I^(C)) was fused in frame with the N-terminal serine (S317) residue of the C-extein (Sav-C) creating I^(C). NI and IC were assembled to a bi-cistronic expression cassette that encoded NI terminated by two stop codons followed by a frameshifted ribosome binding site (SEQ ID NO: 48) and leader sequence for the expression of I^(C). The assembled NI and IC were then cloned between the EcoRI and XhoI site of pBluescript and expressed in E. coli. This bi-cistronic construct express a single transcript with two separate translation products: NI and IC.

Example 19. Protease Activity from In Vitro Trans-Splicing Inteins

Bi-cistronic constructs of various trans splicing intein modified split Savinase were made as described above. Induction cultures, preparation of cell lysates and protease assays were performed as described before. Using the tester intein gp41-1, it was previously demonstrated that split Savinase NI and IC alone had no protease activity and that mixing of splicing disabled NI and IC did not restore protease activity. Protease activity requires trans-splicing mediated joining of inactive protease parts NI and IC and restoration of intact protease sequences (NC). FIGS. 19A and 19B illustrate protease activity from in vitro trans-splicing three hours after IPTG induction. FIG. 19 A illustrates protease activity following splicing of inteins 12, 12, 44, 46, 47, 50, 79, 81 and 103. FIG. 19B illustrates protease activity following splicing of inteins 110, 116, 123, 128, 135, 143, and 150. Variation in protease activity between constructs reflects sequence context specific differences in intein splicing.

REFERENCES

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The references cited throughout this application are incorporated for all purposes apparent herein and in the references themselves as if each reference was fully set forth. For the sake of presentation, specific ones of these references are cited at particular locations herein. A citation of a reference at a particular location indicates a manner(s) in which the teachings of the reference are incorporated. However, a citation of a reference at a particular location does not limit the manner in which all of the teachings of the cited reference are incorporated for all purposes.

It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but is intended to cover all modifications which are within the spirit and scope of the invention as defined by the appended claims; the above description; and/or shown in the attached drawings. 

1. An intein-modified protease comprising: a first precursor and a second precursor: the first precursor comprises an N-extein of a target protease fused to a solubility enhanced N-intein of a trans-splicing intein, and the carboxy terminus of the N-extein is fused to the amino terminus of the solubility enhanced N-intein; the second precursor comprises a solubility enhanced C-intein of the trans-splicing intein fused to a C-extein of the target protease, and the carboxy terminus of the solubility enhanced C-intein is fused to the amino terminus of the C-extein; and the first precursor is separated from the second precursor prior to trans-splicing; wherein the intein-modified protease has enhanced solubility and reduced activity compared to the target protease and the activity of the target protease is restored upon trans-splicing of the intein-modified protease and fusion of the N-extein and the C-extein.
 2. The intein-modified protease of claim 1, wherein the solubility enhanced N-intein comprises an N-intein and a first solubility enhancer, and the carboxy terminus of the N-intein is fused to the first solubility enhancer by a first linker; and the solubility enhanced C-intein comprises a C-intein and a second solubility enhancer, and the second solubility enhancer is fused to the amino terminus of the C-intein by a second linker.
 3. The intein-modified protease of claim 2, wherein at least one of the first solubility enhancer or the second solubility enhancer is independently selected from the group consisting of: a thioredoxin domain Trx, small ubiquitin-related protein SUMO, glutathione-S transferase GST, maltose-binding protein MBP, N utilization substance A NusA, and seventeen kilodalton protein Skp.
 4. The intein-modified protease of claim 3, wherein each of the first solubility enhancer and the second solubility enhancer comprises the thioredoxin domain Trx.
 5. The intein-modified protease of claim 4, wherein the first solubility enhancer comprises, consists essentially of, or consists of an amino acid sequence with at least 90% identity to SEQ ID NO: 51; and the second solubility enhancer comprises, consists essentially of, or consists of an amino acid sequence with at least 90% identity to SEQ ID NO:
 53. 6. The intein-modified protease of claim 2, wherein the first linker or the second linker is a DPNG linker.
 7. The intein-modified protease of claim 1, wherein the target protease is an enzyme selected from the group consisting of: EC3.4.99 proteases, EC3.4.21.62 proteases, keratinases, serine proteases, alkaline proteases, acid proteases, metallo proteases, cysteine proteases, aspartate proteases, ATP-dependent proteases, Subtilisin family proteases, a Savinase, an alkaline protease Q6PNN5, and an acid protease B8NLY9_PEPA_ASPEN.
 8. The intein-modified protease of claim 1, wherein the target protease comprises, consists essentially of, or consists of an amino acid sequence with at least 90% identity to a sequence selected from the group consisting of SEQ ID NOS: 6, 8, and
 9. 9. The intein-modified protease of claim 1, wherein the N-intein comprises an amino acid sequence with at least 90% identity a sequence selected from the group consisting of SEQ ID NOS: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, and 46, the C-intein comprises an amino acid sequence with at least 90% identity a sequence selected from the group consisting of SEQ ID NOS: 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, and 47, and the N-intein and the C-intein together form a trans-splicing intein or variant thereof selected from the group consisting of: gp41-1, Cbu_DnaB, Mja_GF-6P, Mja_Hyp-1, Mja_IF2, Mja_Pol-1, Pab_CDC21-1, Pab_IF2-N, Pab_VMA, Pho_IF2, Pho_VMA, Rma_DnaB, Sru_DnaB, TagPol-1_Tsp-TY_Pol-1, Ter_RIR1-4, Tko_IF2, and Tth-HB27_DnaE-2.
 10. The intein-modified protease of claim 1, wherein the first precursor comprises, consists essentially of, or consists of an amino acid sequence with at least 90% identity to SEQ ID NO: 1, and/or wherein the second precursor comprises, consists essentially of, or consists of an amino acid sequence with at least 90% identity to SEQ ID NO:
 2. 11. The intein-modified protease of claim 1, wherein the first precursor comprises, consists essentially of, or consists of an amino acid sequence with 100% identity to SEQ ID NO: 1, and the first precursor comprises, consists essentially of, or consists of an amino acid sequence with 100% identity to SEQ ID NO:
 2. 12. An expression cassette comprising one or more polynucleotides encoding at least one of a first precursor or a second precursor an intein-modified protease, wherein the first precursor comprises an N-extein of a target protease fused to a solubility enhanced N-intein of a trans-splicing intein, and the carboxy terminus of the N-extein is fused to the amino terminus of the solubility enhanced N-intein; the second precursor comprises a solubility enhanced C-intein of the trans-splicing intein fused to a C-extein of the target protease, and the carboxy terminus of the solubility enhanced C-intein is fused to the amino terminus of the C-extein; and wherein upon expression from the expression cassette the first precursor would be separated from the second precursor prior to trans-splicing, the intein-modified protease would have enhanced solubility and reduced activity compared to the target protease and the activity of the target protease would be restored upon trans-splicing of the intein-modified protease and fusion of the N-extein and the C-extein.
 13. The expression cassette of claim 12, wherein the one or more polynucleotides comprise, consist essentially of, or consist of a sequence with at least 90% identity to SEQ ID NO: 3, and a sequence with at least 90% identity to SEQ ID NO:
 4. 14. A composition comprising: a first precursor of an intein-modified protease and a second precursor of an intein-modified protease, the first precursor comprises an N-extein of a target protease fused to a solubility enhanced N-intein of a trans-splicing intein, and the carboxy terminus of the N-extein is fused to the amino terminus of the solubility enhanced N-intein; the second precursor comprises a solubility enhanced C-intein of the trans-splicing intein fused to a C-extein of the target protease, and the carboxy terminus of the solubility enhanced C-intein is fused to the amino terminus of the C-extein; and the first precursor is separated from the second precursor prior to trans-splicing; wherein the intein-modified protease has enhanced solubility and reduced activity compared to the target protease and the activity of the target protease is obtained upon trans-splicing of the intein-modified protease and fusion of the N-extein and the C-extein.
 15. The composition of claim 14, wherein the solubility enhanced N-intein comprises an N-intein and a first solubility enhancer, and the carboxy terminus of the N-intein is fused to the first solubility enhancer by a first linker; and/or the solubility enhanced C-intein comprises a C-intein and a second solubility enhancer, and the second solubility enhancer is fused to the amino terminus of the C-intein by a second linker.
 16. The composition of claim 15, wherein the first solubility enhancer or the second solubility enhancer is selected from the group consisting of: a thioredoxin domain Trx, small ubiquitin-related protein SUMO, glutathione-S transferase GST, maltose-binding protein MBP, N utilization substance A NusA, and seventeen kilodalton protein Skp.
 17. The composition of claim 16, wherein each of the first solubility enhancer and the second solubility enhancer comprises the thioredoxin domain Trx.
 18. The composition of claim 17, wherein the first solubility enhancer comprises, consists essentially of, or consists of an amino acid sequence with at least 90% identity to SEQ ID NO: 51; and/or the second solubility enhancer comprises, consists essentially of, or consists of an amino acid sequence with at least 90% identity to SEQ ID NO:
 53. 19. The composition of claim 15, wherein the first linker or the second linker is a DPNG linker.
 20. The composition of claim 14, wherein the target protease is an enzyme selected from the group consisting of: EC3.4.99 proteases, EC3.4.21.62 proteases, keratinases, serine proteases, alkaline proteases, acid proteases, metallo proteases, cysteine proteases, aspartate proteases, ATP-dependent proteases, Subtilisin family proteases, Savinase, alkaline protease Q6PNN5, and acid protease B8NLY9_PEPA_ASPEN.
 21. The composition of claim 14, wherein the target protease comprises, consists essentially of, or consists of an amino acid sequence with at least 90% identity to a sequence selected from the group consisting of SEQ ID NOS: 6, 8, and
 9. 22. The composition of claim 14, wherein the N-intein comprises an amino acid sequence with at least 90% identity a sequence selected from the group consisting of SEQ ID NOS: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, and 46, the C-intein comprises an amino acid sequence with at least 90% identity a sequence selected from the group consisting of SEQ ID NOS: 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, and 47, and the N-intein and the C-intein together form a trans-splicing intein or a variant thereof selected from the group consisting of: gp41-1, Cbu_DnaB, Mja_GF-6P, Mja_Hyp-1, Mja_IF2, Mja_Pol-1, Pab_CDC21-1, Pab_IF2-N, Pab_VMA, Pho_IF2, Pho_VMA, Rma_DnaB, Sru_DnaB, TagPol-1_Tsp-TY_Pol-1, Ter_RIR1-4, Tko_IF2, and Tth-HB27_DnaE-2.
 23. The composition of claim 14, wherein the first precursor comprises, consists essentially of, or consists of an amino acid sequence with at least 90% identity to SEQ ID NO: 1; and/or the second precursor comprises, consists essentially of, or consists of an amino acid sequence with at least 90% identity to SEQ ID NO:
 2. 24. A home care product comprising an intein-modified protease of claim 1, or the composition of claim
 14. 25. The home care product of claim 24 further comprising one or more effectors, wherein the one or more effectors is capable of suppressing trans-splicing.
 26. The home care product of claim 25, wherein the suppressing is reversible.
 27. The home care product of claim 25, wherein the home care product further comprises at least one agent selected from the group consisting of: detergent, soap, industrial cleaner, and dish washing liquid.
 28. The home care product of claim 25, wherein the one or more effectors are selected from the group consisting of: sodium salt supplements, potassium salt supplements, ammonium salt supplements, charged polymeric salt supplements, polyol supplements, sodium chloride, tetrasodium iminodisuccinate, disodium succinate, disodium tartrate, potassium lactate, potassium citrate, potassium chloride, sodium nicotinate, ammonium sulfate, ammonium nitrate, lithium citrate, sodium polyaspartate, sodium polyacrylate, tetraethylene glycol, polyethylene glycol, tetraglycol, propylene carbonate, mono propylene glycol, glycerol, and tomadol.
 29. (canceled)
 30. A method of regulating protease activity comprising forming the home care product of claim
 24. 31. The method of claim 30, wherein forming comprises combining the home care product with one or more effectors and at least one agent to form a mixture, wherein the at least one agent is selected from the group consisting of: detergent, soap, industrial cleaner, and dish washing liquid.
 32. The method of claim 30 further comprising causing splicing of the intein-modified protease in the mixture.
 33. The method of claim 31, wherein the one or more effectors includes potassium chloride.
 34. The method of claim 33, wherein the potassium chloride concentration is in a range from 0.1 M to 5.0 M.
 35. The method of claim 34, wherein the potassium chloride concentration is in a range from 0.5 M to 2.0 M.
 36. The method of claim 32, wherein the step of causing splicing includes diluting the mixture with a liquid to a mixture:liquid ratio of less or equal to one selected from the group consisting of: 1:5, 1:10, 1:20, 1:50: 1:60, 1:70, 1:80, 1:90, 1:100, 1:150, 1:200, 1:250, 1:300, 1:350, and 1:400 of a mixture to liquid.
 37. The method of claim 36, wherein the liquid is one of water and an aqueous buffer.
 38. The method of claim 32, wherein the protease activity of the target protease is obtained upon splicing of the intein-modified protease.
 39. A method of storing a protease in a mixture comprising: making an intein-modified protease of claim 1 or the composition of claim 14 and combining the intein-modified protease or the composition with at least one agent selected from the group consisting of: detergent, a soap, an industrial cleaner, and a dishwashing liquid and one or more effectors to form a mixture. 